A village on the east coast of England that has almost completely eroded into the North Sea.

The world's largest prehistoric copper mine had 30,000 animal bones scattered throughout the maze of passageways.

Built to hold the worst of the worst of the Nazi war prisoners.

This antique prison is a tourist attraction with a sordid past.

The abandoned funicular tunnel was a secret base for the BBC during World War II.

The ornate structure is part of a building boasting more marble than the Vatican.

This lonely cast-iron structure is the only wave-washed lighthouse of its kind left in all of Britain.

A historic hill of tall tales, with one rather special tree.

Where the sleeping monsters of Scotland's oil industry are left to rust.

Each spring this woodland floor is carpeted with purplish flowers as far as the eye can see.

A spooky juxtaposition of caves and graves gives this legend-filled cemetery a particularly haunting vibe.

Near Birmingham, England three and a half miles of top-secret tunnels housed a World War II “shadow factory” and a Cold War nuclear bunker.

This romantic, decaying 13th-century ruin on the edge of Sherwood Forest is reputedly one of England's most haunted places.

Enter this small nook and you'll be surrounded by 360 degrees of street art.

High Victorian fantasy created a fairytale castle out of a ruined fortress in Wales.

A sea cave with a waterfall and Viking past

You'd never know the houses at 23-24 Leinster Gardens were fakes—until you see the train tracks on the other side.

Putting the "mod" in "modular" since 2000.

A serene public space nestled within the remains of Glasgow’s Victorian maternity hospital

Local legends say that fairies used to dance in the moonlight here and invite handsome young men into their grottoes.

A labyrinthine underworld of tunnels and caverns hides beneath the city.

A mysterious bridge over a sunken Roman road.

The broken skateboards that became a poignant memorial to a murdered skater.

The ruins of this medieval castle in Northern Ireland have inspired artists from C.S. Lewis to Led Zeppelin.