(Kate) From its pebbled beaches and rugged cliffs to its seaside towns and fish and chips, I love the British coast.

Ah, look at that!

Beautiful, beautiful.

The birds, the flowers, and most of all, the sea.

♪ So, across this series, I'm taking a journey along some of the most beautiful walks in the world.

♪ These footpaths, gloriously uncluttered.

I'll be meeting the people who live... (Bill) So, if they're alive and big enough to eat, they go into that basket.

(Kate) ...and work along them... -Wow!

-Oh, look!

(man) Both the sunshine and the dolphins were ordered special.

(Kate) ...as I discover paths I've never walked before... -It is a kind of sci-fi set.

-It is.

-You don't think England.

-No.

(Kate) ...and reveal the secrets of ones I know well.

(man) It's a dinosaur's footprint.

-No, it can't be!

-Yeah, toe here.

-Oh, you are right!

-Another toe there.

♪ (Kate) It is heaven.

If I didn't have so far to walk, I'd just sit on here all day.

(laughing) (spirited music) Today, I'm exploring a special shingle shoreline...

It's a real coast of contrasts.

It has this incredible feeling of space and wildness and a kind of untouched feel even though it's not untouched.

...discovering a top-secret nuclear bunker... You're never quite sure whether you want to go in somewhere like this.

This is kind of fascinating and a bit scary at the same time.

...watching for wildlife on the water... Oh, look at that pup.

It is absolutely covered in mud.

...and combing some of the most important beaches in the world.

-She's got treasure.

-I've got treasure.

♪ (guitar music) ♪ (birds squawking) ♪ My walk today takes me along a 12-mile stretch of Suffolk's shingle coast.

♪ I'm starting at Minsmere Nature Reserve, a place I know well, before heading down the pebble beach past Sizewell B power station and the Edwardian fantasy holiday village of Thorpeness.

At Aldeburgh, I'll turn inland following the ancient Sailors' Path to Snape Maltings, where I'll cross the River Alde and explore the estuary.

I'll then head to the historic town of Orford before finishing up on one of the largest and most unusual shingle habitats in the world at Orford Ness.

(waves whooshing) On the face of it, this coast looks quite monochrome, like it's all one one level.

But because you're not distracted by endless features, you become entranced by little details.

I mean, even just sitting here, what I love is the kind of contrast between the solemn sea, the sound of the small waves coming up against that shingle, the different colors of the stones coming into this cropped grass and the wildflowers.

I know it sounds daft, but there's something lovely about concentrating your mind on the little details, and I think that's what this walk is going to do for me.

♪ Our coastlines have formed our first line of defense for thousands of years.

♪ But it's the Second World War that has left its indelible mark here.

♪ During the early years of World War Two, one of the greatest fears was, of course, invasion, and this coast was particularly vulnerable because just over a hundred miles that way was Nazi-occupied Holland.

So, you see quite a lot of these installations along this coast.

They are tank traps.

The idea was that if anyone landed with tanks on the beaches and tried to steam inland, they wouldn't be able to get very far.

Not entirely sure how effective they would've been.

Also, you can't help thinking that they could've just driven around the end there.

(bluesy music) ♪ The first part of my walk is slightly overshadowed by the Sizewell B power station, but the trick is to put it behind you.

♪ It just seems so incongruous to have a building like that and, then, literally just over that little dune you could stand and look out at all that sea... ♪ ...and not believe it was here.

Which is exactly what everyone on the beach today seems to be doing... ♪ ...and getting to enjoy an outlook that hasn't changed that much from days long before the power station arrived.

♪ Look at all that.

Just that vast expanse of the North Sea.

(soft music) You could be forgiven for not realizing that the beaches here are not only beautiful, but very rare.

♪ To discover what's so special about them, I'm meeting another Kate just behind the shoreline.

♪ I know that the Suffolk Coast is famous for its shingle beaches, these miles and miles and miles of shingle beaches, but I never thought of them as a place where plants grew.

I suppose I never really thought of them -as a habitat.

-There are lots of places in the world that have shingle, but it's moving all the time.

The stones the other side of that beach will be half a kilometer down the coast in two weeks, but where it's stable enough and deep enough.

So there are places here along the Suffolk Coast where the shingle goes down 18 meters.

-Are you serious?

-Eighteen meters.

-Look how it's thriving.

-Yeah.

(Kate Osborne) Beaches like this are only found in three places in the world.

-That's us... -Yeah.

(Kate Osborne) ...Japan, and New Zealand.

And that's it.

(Kate) That is an absolutely amazing statistic.

Life here in the gravel is tough, and each of its inhabitants has evolved especially for the job.

One of my favorite shingle plants has always been the sea kale, which thrives in these conditions.

-See the seed head... -Right.

(Kate Osborne) ...and they dry out.

I've probably got some.

Now, try and break one of those open.

I actually had to crack these open with a hammer.

(Kate) Oh my goodness, yeah, it's absolutely rock-hard.

(Kate Osborne) Nature is incredible.

It can survive for up to five years at sea.

And what's so clever about nature is it's this dry seed coat.

If the conditions are right and it washes up on a shingle beach where it could live, 'cause it doesn't like sandy beaches, the shingle actually abrades, rubs open the seed coat, and then it will germinate.

That is so clever.

See, I am now looking at shingle in a completely different way.

(energetic music) ♪ Hoping her passion for Suffolk shingle beaches will rub off, Kate runs regular beachcombing expeditions.

And before I head on, she wants me to have a go.

Now are there any rules around beachcombing?

I'm sort of thinking a little bit like kind of metal detectorists or anything like that.

Are there things that you shouldn't touch or you can't take?

(Kate Osborne) Basically, other than litter, you should be leaving anything you find behind.

And seaweed and driftwood are the two most important things you can leave on the beach.

♪ So, it's just what can you find basically.

(Kate) It's literally just pick up anything... (Kate Osborne) Anything that looks cool, yeah, absolutely anything.

♪ Um, I reckon that's an oyster shell.

♪ (Kate Osborne) How are you doing on the treasures front?

(Kate) I've got some quite good treasure, I think.

It's completely addictive.

I can see exactly why you do this.

♪ -Shall we compare finds?

-We have to be careful not to lose our treasures in the wind, though.

This white thing that you found... (Kate) Yeah, I'm assuming it is some sort of seaweed, is it?

(Kate Osborne) It's an animal.

So if you hold it up to the light and look through it, you'll see it's full of tiny little holes like lace, plaster, skin.

So, every hole has an individual creature -living in it.

-How amazing.

(Kate Osborne) These are the egg cases of skates and rays.

-You have got a shark egg case.

-Is that a shark?

(Kate Osborne) So, this is what, our age, we'd probably call a dogfish.

-Yes.

-That has now been renamed confusingly to a small-spotted catshark.

(Kate) Yes, they stay in shallow water on the coastlands and, yes.

-As do the skates and rays.

-Yes.

That's absolutely brilliant.

Kate, it's been fascinating.

And I promise on the rest of my walk that I will treat the shingle with the delicate care that it deserves because it is a remarkable habitat.

-Thank you.

-Thank you very much.

(classical music) ♪ (Kate) A mile along the coast you come to Thorpeness, one of only two permanent holiday villages in the UK.

♪ It was the brainchild of a barrister who dreamt of creating an exclusive family resort for the rich and well-to-do.

♪ Opening just as World War One began, its eccentric mix of mock Tudor housing and a boating lake complete with Peter Pan-inspired islands proved an instant success.

♪ More than a hundred years later, it continues to attract tens of thousands of visitors every summer.

♪ (energetic music) Looks almost like it's just been washed up.

Coming up, a quintessentially English seaside town.

"Could any town be more pleasant to come to than this, with its quaint sea-fretted beach?"

I explore the notorious Sailors' Path...

It feels like I'm miles away from the sea here.

...and meet an unexpected family enjoying the sunshine.

Oh, how lovely.

Look at that pup.

It is covered in mud.

(violin music) ♪ Today, I'm walking a 12-mile stretch of Suffolk's shingle coast.

And it's a coastline of contrasts, where rare pebble beaches give way to a fantasy holiday village... ♪ ...and an almost overwhelming sense of the land, of the sea, of everything being flat.

But it's a place that pulls your emotions in all sorts of ways.

♪ My next stop is the ancient town of Aldeburgh, and I leave the beach at Maggi Hambling's giant metallic shell honoring one of Britain's best known composers.

♪ This is the Scallop.

This rather amazing piece of sculpture, a kind of homage to Benjamin Britten who, of course, lived and worked in Aldeburgh.

And it caused all sorts of controversy when it was put here on the beach.

People liking it to a bit of rusty, old tin can.

I think it's absolutely beautiful.

It looks almost like it's just been washed up, and it just sits perfectly in this landscape.

♪ Now a bustling seaside town, Aldeburgh was a very different place when Benjamin Britten moved here in 1947.

♪ So I've just walked into Aldeburgh proper which this book, The King's England: Suffolk, published in 1941, describes like this: "Could any town be more pleasant to come to than this, with its quaint sea-fretted beach and three streets in a row?"

I think it's quite a lot more than three streets now.

"On the beach," and this is still true, "On the beach stands the old Moot Hall," which is this extraordinary building here.

"Today, the Moot Hall stands all unafraid of the advancing sea.

Perhaps it remembers that Aldeburgh sent the Marigold to sail with Drake against the Spaniards."

I think I read somewhere that this used to be in the middle of town and that, effectively, the sea has just sort of nibbled away at the coastline and it's ended up more or less on the beach.

It's a rather lovely building.

(guitar music) It's also a reminder of how important Aldeburgh was in Tudor England.

Five hundred years ago, it was a world-leading port and center of shipbuilding.

♪ But when the river silted up, the big ships could no longer dock and with them went its power.

♪ Today, Aldeburgh is best known for the international music and arts festival, started by Benjamin Britten, and its food... ranging from traditional fish and chips to something far more cutting edge.

-Hi, Jeong-un.

-Hi, Kate!

-How are you?

-So lovely to see you!

(Kate) What a beautiful, beautiful day.

Since settling here with her family, Jeong-un has started a business using the best local seasonal produce to make a Korean dish of fermented vegetables called kimchi.

Korean street food is not something I really expected to come across in Aldeburgh.

-Yes.

-Let's start with kimchi because from what I know, it is like the foundation stone in Korean cuisine.

-Is that right?

-Yes, it's a staple side dish.

-Yeah.

-So, it comes every meal, for breakfast... -Really?

-...lunch and dinner.

All the time.

In Korea, every family, every household has a different recipe.

Depends on where you come from.

-Right.

-We lived seaside, so you get lots of fresh seafood in the kimchi.

(Kate) So this one is very appropriate for Aldeburgh -'cause we're by the sea.

-Yes!

(Kate) Jeong-un's secret family recipe needs to ferment for at least a week before it's ready to eat.

Gonna try a bit, but I'm gonna-- I've got a huge amount here.

Uh, uh, uh, mm, mm.

(Jeong-un) Brave.

Mm, delicious.

(Jeong-un) Is it spicy enough for you?

(Kate) I could go a little bit spicier, but it's really nice because it's not an overwhelming spice.

-Yes.

-It's got a lovely kick to it.

You eat this for breakfast, you said?

-Yes.

-That would be perfect for breakfast for me.

(Jeong-un) I think you're half Korean.

(laughing) (Kate) You know what I think about kimchi?

It's excellent walking food.

So, can I take these two with me?

-Yes.

-And they will fuel me along the Suffolk Coast.

Thank you.

See you again.

Bye.

(bluesy guitar music) ♪ From here, my walk turns inland, following the ancient Sailors' Path along the River Alde to Snape Maltings.

♪ That tree, isn't that lovely?

Within minutes, I'm a world away from the wide-open skies and shingle beaches.

It feels like I'm miles away from the sea here, deep in these rather lovely birch, fir, and chestnut woodlands.

♪ The other thing is how quiet it is here.

No people.

It is extraordinary.

I always think that you walk a little bit further than most people are prepared to walk and you have it all to yourself.

It wasn't so lovely in the old days, apparently.

It's called the Sailors' Path because sailors who docked at Snape, which is where I'm heading, if their boats got stranded in the mud when the tide went out, they would have to walk to Aldeburgh, which is that way.

And, um, this was a path full of kind of smugglers and ne'er-do-wells, basically, who would leap on unsuspecting sailors and rob them.

Chance be a fine thing meeting a ne'er-do-well.

Ooh, how exciting.

What a contrast.

Out of the woods into the reed beds.

(uplifting music) ♪ Just ahead at Snape Maltings, I'm heading back onto the coastal walk and into an area of protected wetlands.

♪ It's rumored to be incredibly beautiful and rich with animals and birds.

(birds chirping) And I think I found the perfect way to see it.

♪ -Hey, Jamie.

-Yeah, I am, yeah.

(Kate) Could you have organized a more beautiful day?

(Jamie) It's stunning, isn't it?

Absolutely stunning.

(Kate) Right.

Is the plan to go out on that river?

-Yeah, let's go for it, yeah.

-Could we do that?

(Jamie) Grab your oar and a life jacket.

-Great, lead on.

-Come on, follow me.

You shove us off.

(guitar music) ♪ -This is heaven.

-Beautiful, isn't it?

(Kate) Isn't it?

♪ Jamie started volunteering for the local wildlife trust as a boy and is now one of their wardens.

♪ (Jamie) We're about four miles from the sea as the crow flies, but actually, where we are now is 18 miles from the mouth of the river.

-Eighteen miles?

-Eighteen miles, yeah.

(Kate) From where the river goes out into the sea?

(Jamie) That's it, yeah.

(Kate) That's extraordinary!

(Jamie) So, as the (indistinct) pushed down the shingle ridge, it's actually pushed the river further inland.

(Kate) I'm guessing, though, because it is still an estuary and you've got all these wonderful mud flats, -it's teeming with wildlife.

-Yeah.

Like your redshank and your avocet.

-Yeah.

-Curlew, black-tailed godwit.

And we just got a few maybe immature gulls here just on the left.

-Are those black-headed gulls?

-Black-headed gulls, yeah.

Plenty of little egrets about, all sitting on the water's edge and waiting for some of the shore crabs and fish to swim past.

Such a treat to see those birds these days.

♪ We can see some seals as well.

-Really?

Where?

-Just to the left of where that red-orange bit on the tree.

(Kate) Oh, yes!

Oh, look at these little seals ahead of us!

♪ So these are common seals, presumably, are they, Jamie?

(Jamie) Yeah, so these are common seals.

We get two species of seal in the UK.

-Yeah.

-We've got the common seal and the gray seal.

So, as you can see, these ones have got a real lovely puppy dog expression.

(Kate) They have--they look a little bit -like Labradors, don't they?

-They certainly do, yeah.

The gray seals have a much longer nose and aren't quite so fortunate in the looks department.

(Kate) Oh, is there a third one there?

-That's the pup.

-Oh, it is.

Oh, Jamie, look.

Oh, look at that pup.

It is absolutely covered in mud.

They're very orange.

I don't think I've ever seen a common seal -that color before.

-So, that's because the fur extracts the iron from the mud.

-Oh, is that why?

-It creates this almost, like, rusty color.

(Kate) Yeah, one of them looks like he's almost got -a go-faster stripe.

-Yeah, it does, doesn't it?

(Kate) Oh, how lovely.

(Jamie) Within a couple of hours of a common seal pup being born, they can actually go and dive in with the mother.

-That's extraordinary.

-So they can almost give birth between low tide and high tide, and by the time it's immersed in water, the pup is ready to go off and dive in with the mother.

(Kate) That's amazing.

(uplifting music) ♪ Well, that was fantastic.

-Thank you so, so much.

-No, you're very welcome.

-That was excellent.

-Nice work.

♪ Coming up... One of the rarest shingle landscapes on our planet.

I can't think of anywhere else that's like this.

-It's sort of so otherworldly.

-It is.

You don't think Suffolk Coast.

(Kate) And I face my foodie demons with a true taste of the sea.

(Bill) I wouldn't try and slide it down in one.

(Kate) Right.

You would chew it.

-Definitely.

-Okay, let's go.

(uplifting violin music) ♪ I'm over halfway along my Suffolk walk today... ♪ ...heading to Orford Ness and one of the most unusual shingle landscapes in the world.

♪ So far, I followed the path along rare pebble beaches... ♪ (waves whooshing) ...and through a protected estuary wetland.

(birds chirping) ♪ I'm now taking the woodland route to my next rendezvous.

♪ It's just incredibly quiet here.

Can't hear the sea even though it's just over there.

There's nobody about.

There's no traffic sound.

The only thing you can hear if you pause... is just the wind very gently rippling through the silver birch trees.

♪ I'm now heading to the ancient town of Orford which lies downstream on the River Alde.

♪ Its 800-year-old castle keep is a reminder of the town's standing as an important coastal defense under Henry II.

♪ And in the neighboring churchyard, there's more evidence of how vulnerable this coastline was during World War Two.

♪ There's a really touching memorial here.

"In remembrance of those of the parish who were killed in the air-raid on Orford on the 22nd of October, 1942."

And at the bottom of the main stone, there's Pauline Cicely Chambers, 11 years; Robin Arthur Chambers, eight years; Neville Frank Chambers, four years.

Mm.

(piano music) ♪ I'm now heading out of town to the river... ♪ ...where I'm meeting the head of a family that moved here just after the war.

(engine starting) When you wander around Orford, there's a name that crops up time and time again and it's Pinney.

That man out there is Bill Pinney.

His dad came here just after the war, and he discovered that this river had once been a very successful oyster fishery, and he thought, "I'll revive it."

And everyone said, "If you want to lose all your money, go into oysters."

Little did they know.

Have you found treasure, Bill?

(Bill) Yeah, I have.

(Kate chuckles) (Kate) Today, the oysters are still thriving, and the family business now includes a restaurant and smokehouse.

So, what do we need to sort here?

(Bill) Anything that's big enough to eat, so anything that size and above.

So, if they're alive and big enough to eat, they go into that basket.

And then you've got small ones in there?

-Yeah.

-Well, they're gonna go back in the river, so they go in that basket.

-So they get a reprieve.

-Yes, they get another go.

(Kate) It's quite a good proportion of good ones, though.

(Bill) Yes, there is, yeah, yeah.

(Kate) So, how come they're here?

Why does this work?

(Bill) The oysters come to us as a very, very small seed from an oyster hatchery.

-Oh, really?

-Yeah.

They're absolutely tiny, I mean, they're probably no bigger than that, you know, about four millimeters in size.

Then we put them in bags on the surface of the river... -Right.

-...and they feed off the plankton in the river.

-Yeah.

-In this particular creek, you know, they've been growing here since Roman times.

It's well-known as a fattening ground, waiting for them to get bigger and bigger and bigger until they reach about this size.

At that stage, they're big enough to look after themselves.

So, we throw them on the bottom and they can live under their own steam.

(Kate) So you have to do quite a lot -of kind of oyster husbandry.

-Oh, yeah.

(Kate) I read that your father, who started this whole venture, was told that if he wanted to lose all his money, it was to start an oyster fishery.

-That's right, yeah.

-But I thought oysters were always a kind of luxury food.

(Bill) They have that description of being a luxury food, but they also suffer their natural disasters.

They had a natural upset with a typhoid outbreak in late Victorian times when nearly everybody went off eating them.

Of course, nowadays, the oysters are purified and you don't get typhoid in rivers, so that might have been part of it.

(Kate) Right.

So, did you grow up eating oysters?

(Bill) Yeah.

In our shop, there's a picture of me when I was about five years old -eating an oyster.

-Eating an oyster.

(Bill) I didn't used to be a massive fan of them, but I really am now, so... -Are you?

-Yeah.

(Kate) You're gonna have to teach me 'cause I'm not a massive fan, I've never-- My husband, I must say, he absolutely loves them.

But, yeah, I'm not quite there yet, so we'll see.

(guitar music) ♪ They don't need much preparation... (Bill) Here.

(Kate) ...beyond a vigorous power shower...

When you clean them off like that, they are absolutely beautiful things, aren't they?

...followed by a two-day-long purifying soak to clean out the grit.

It looks like they're in a bubble bath, Bill.

(Bill) Yeah, it does, doesn't it?

(Kate) And, then, they're ready to eat.

It's really interesting you wanted to take over this business because it's a tough business.

Did you want to take it over, or did your dad just say... (Bill) I just sort of fell into it, really, but we've always-- I've always handled and grown the oysters.

(Kate) And from what I understand, there's another generation who have also-- There's a generation coming up behind us, yeah, yeah.

(Kate) Does it feel very pleasing that you've got this now three-generation legacy in this part of... Yeah, it's very nice, yeah.

It is, yeah, it's lovely.

-Shall we make it a small one?

-Make it a small...

Yes, if you could.

So, the technique for eating them, it's sort of down in one, isn't it?

(Bill) Some people say that, I think you don't get the full flavor of it if you don't eat it like normal food.

I wouldn't try and slide it down in one.

(Kate) Right, you would chew it.

-Definitely.

-Okay, right.

Okay, let's go.

Mm.

God, it r--I mean, it is the full flavor of the sea.

(Bill) Yeah.

Quite sweet as well.

(Kate) Yeah, it is.

And it's a very delicate, almost a mousse-like texture.

I was slightly expecting that kind of rubbery... "Ooh, I really have to get through it and then be polite to Bill."

But I didn't have to be polite.

Bill, you might have turned me.

I might, at last, be sophisticated enough to say that I quite like oysters, if they've been grown by Bill anyway.

(soft music) ♪ (gate clicking) ♪ Just across the river lies my final destination... ♪ ...the ten-mile long shingle spit and national nature reserve, Orford Ness.

♪ It's where the shingle from all the beaches of Aldeburgh and further north washes up.

And for almost a century, it was also a top-secret military test site.

It's now looked after by the National Trust, who've arranged for me to visit both the test site and see the shingle spit.

-Hello!

-Are you Glen?

-I'm Glen.

-Lovely to see you.

Can I just jump on?

(Glen) Yeah, welcome aboard.

♪ (Kate) Orford Ness, was it formed by, basically, the movement of the sea?

(Glen) Exactly that, the whole of the Suffolk Coast is moving because of erosion.

And it formed about 5,000 years ago.

It's the largest shingle spit in Europe, so it's quite rare and it's very fragile.

The shingle is thrown up into ridges that traps tiny bits of organic matter.

That's where the plants grow.

And, then, over time, that repeats century after century, again and again.

(Kate) And something that I've seen throughout this walk is lots of coastal defenses and got that real sense of how vulnerable this part of our coastline was during the war.

(Glen) It is, I mean, here, we call it the island.

It is attached to the mainland, but it's, in theory, an island.

The military used that for 80 years because of its location, because of that sense of remoteness as a top-secret military base for First World War, Second World War, and through to the Cold War.

(Kate) Oh, so this was actually a military base as well as a sort of defense-- a defensive line?

(Glen) Indeed.

(guitar music) ♪ The most extraordinary landscape, isn't it?

I can't think of anywhere else in the UK that's like this.

-It's sort of so otherworldly.

-It is.

You don't think Suffolk Coast.

♪ (Kate) After decades of use as a military test site, the trust is now working to encourage wildlife back to this unique shingle spit.

♪ (sheep bleating) ♪ They're using this rather special herd of sheep to help them graze the land back to a more natural state so it attracts insects, birds, and animals to set up home here.

(Andrew) Come, boy.

(whistling) (Kate) Andrew, the shepherd, has been managing the flock for the last ten years.

-We started with just 29 sheep.

-Right.

(Andrew) And over the years, we've built up the numbers.

Ideally, we'd like about 500.

(Kate) But I thought that sheep basically just graze everything down and there is no habitat.

(Andrew) We've picked breeds that do different jobs.

The Whitefaced Woodlands, they like the poor pasture.

-Right.

-The Manx Loaghtans, originally from the Isle of Man, been around thousands of years, they like the broadleaf plants.

Good boy.

Where we're gonna move the sheep through today is kind of like the main bird nesting site.

-Right.

-And they can carry on with their work and get the habitat right for all the ground-nesting birds who can come next spring.

(Kate) It's the most extraordinary landscape, this.

There's sort of the mixture of the military stuff and the concrete.

It kind of isn't obviously beautiful, but it has a beauty, doesn't it?

(Andrew) Oh, immensely, yeah, it's like going into a different world.

It's definitely an area for big skies.

(Kate) Yeah, and it is fantastic for wildlife.

(Andrew) Yeah.

(mellow music) ♪ (Kate) So this is it now, this is where-- (Andrew) This is it, yeah.

They've got six weeks in this area to get it in tip-top condition for all the ground-nesting birds who can come next spring.

(Kate) It's just...

It's such a wonderful thing.

Thank you very, very much, Andrew.

♪ (uplifting music) Coming up...

It's like coming into a sci-fi set.

My walk ends on one of the country's most secret military research sites... -So, can we go in?

-We can go into this one.

-Can we?

-Yeah, have a look inside.

(Kate) Oh, it's a bit scary.

...as I enter a lab which tested the British nuclear bomb.

(Glen) You can see the roof structure is quite lightweight, so if something went wrong, the roof could easily blow off.

♪ (soft music) ♪ (Kate) I'm walking across Orford Ness, the ten-mile long shingle spit that marks the end of my Suffolk walk.

It's just the most extraordinary landscape.

I can't think of anywhere else in the UK.

There's sort of no parallels, are there?

And I'm about to enter the former military test site, an area that, for decades, was so secret, that even the people who worked there didn't always know what it was they were researching.

♪ It's like coming into a sci-fi set.

(Glen) It is, it is that sort of strange lunar landscape with these strange buildings.

(Kate) Yes, talking about these strange buildings, what on earth are they doing here?

(Glen) So, the buildings here are from when the Atomic Weapons Research Establishment worked on Orford Ness from the 1950s through to 1970s.

They had six of these buildings, each what they called labs, all looking at testing elements of the very first British nuclear bombs.

(Kate) Wow, and presumably, they did it here because it was so remote and inaccessible.

(Glen) Yeah, the military had owned it since the First World War, moved on into the Second World War, only work on radar.

Winston Churchill saw his first blip -on a radar screen here.

-No.

Really?

(Glen) They were doing work during the Second World War on bomb ballistics, how bombs fall from planes, all that sort of aerodynamics.

So they owned the land, and then, for here, Cold War moved on to nuclear because it's partly quiet, it's remote, and as you can see on the side of these buildings, you've got shingle that you can use for banking to add some sort of bulk to these large buildings.

(Kate) Were they actually doing nuclear testing here?

Were they blowing things up?

(Glen) No nuclear material being blown up, but to get nuclear bombs to work in that period, there's still quite a large bit of conventional explosives required to push the two parts of the nuclear bomb together.

They didn't want that bomb to go off accidentally when it's on a plane being vibrated, heat and cold.

And each of these buildings were created for stress testing the casing and the fuse mechanisms just to check that they would withstand the forces required.

-So, can we go in?

-We can go into this one.

-Can we?

-Yeah, have a look inside.

(Kate) Oh, it's a bit cr-- I'm never quite sure whether you want to go in somewhere like this.

It's kind of fascinating and a bit scary -at the same time, isn't it?

-It is.

I think the interesting fact is, as well, they have the same legal status as Stonehenge.

They are scheduled monuments.

-Really?

-Yes.

So they are protected for the nation because of their uniqueness.

♪ This is lab one of six of... (Kate) So, do we know what was done here?

(Glen) Yes.

This lab in particular was looking at vibration testing -on the casing.

-Right, okay.

(Glen) In front of us we've got which now looks just like a puddle, but below that water is a nine-feet deep pit, and they would drop the bomb in there and attach all the vibration units to it.

We can see the roof structure is quite lightweight, designed that if something went wrong, the roof could easily blow off.

(Kate) Right.

And did the people living in picturesque Orford have any idea of what was going on here?

Because if people are coming back and forth, they must have thought, "Well," you know, "what are they coming here for," or... (Glen) There's anecdotes or reports of people hearing muffled bangs on the horizon.

The buildings are still standing, so nothing went wrong as such, but obviously, there were still bangs happening, so they could hear the noise.

They knew probably in general what was happening, but not the detail, and that really continued.

And I remember--I grew up locally.

As a primary school student, you were brought to Orford Castle for your summer outing, standing up on the battlements.

And this was at the period the military still owned it, but it stopped work here.

And I stood there on the battlement looking out at these strange buildings on the horizon as an eight-, nine-year-old and saying, "What's that?"

The local guide said, "What do you mean?

There's nothing there."

-But I can see it.

-"I can see them."

(Glen) Yeah, the village were that protective of what was going on here that they even denied that you could see anything.

♪ (Kate) It's absolutely fascinating, and the weirdest thing, Glen, is standing here and looking back at a classic pastoral English scene: Orford Castle there, the beautiful church, and the little village, and here we are in a nuclear testing site.

(Glen) But there's actually a continuation.

You've got, you know, the castle is -a building of war.

-I suppose so, yeah.

So this is, in a way, a continuation.

When you look out of here on a clear day, you can see the dome of the nuclear power station at Sizewell.

Again, that knowledge would've been shared, what they were learning becomes (indistinct).

There's a timeline, you can flow through the landscape.

-It just all connects.

-Yeah.

We all like the idea of a landscape being pristine, but actually, there's no such thing in this country.

Everything has had kind of man's hand on it, -if you like.

-Especially here, the Ness is shaped by its very nature, by changing forces, both natural and man.

Where the coastline is changing, the Ness is growing in places, eroding in others.

So, a constant state of flux really sums up Orford Ness.

Yes, it's been shaped by man, but also nature.

(Kate) Yeah, yeah.

It's a really bewitching and fascinating place.

-Thank you for showing me it.

-You're welcome.

(mellow music) ♪ (Kate) It's amazing, this bit of coastline.

I think it is its history that comes alive when you're walking along it, so when you see the relics and remnants, and you're walking past them and you can touch them, and you can look out across that vast expanse of the North Sea and really imagine what it must have been like to feel kind of under threat of invasion.

I think what is perhaps surprising about this bit of the coastline is that away from the kind of more obvious attractions of Aldeburgh and then the picturesque Orford that brings people in in their droves, it does have this wildness and it does have this charm that sort of gets under your skin.

I think it is that extraordinary expansive sky and how it meets the horizon across the North Sea, and a feeling of space and an area that actually still, even today, has a kind of slightly edgy element, that it hasn't quite been tamed.

♪ (spirited music) ♪ (bright music)