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

The secret wartime bunker built on the platforms of an abandoned Tube station.

An engineering error ensured this cavernous 350-foot-long subterranean thoroughfare was never used as intended.

A wonderfully eclectic Victorian aquarium lies in the basement of the Horniman Museum.

A friendly pub with a sordid past in cock fighting.

The "lost friend” is the most famous of the six moai statues that were removed from Easter Island.

This beautiful "lagoon" is actually a toxic soup filled with cars, carcasses, and trash. When warnings couldn't stop people from going for a dip, the town dyed it black.

This foolish Victorian sea fort was converted to a deluxe hotel.

It's believed a local adventurer spent 50 years living inside this cave.

Stonehenge has nothing on Castlerigg’s views.

No one knows who created the statues or if they are arranged properly—let alone the artwork's real name.

"We gonna rock down to Electric Avenue, and then we'll take it higher..."

Harry Potter once visited this massive limestone cliff, which was carved by an ancient glacial river.

The rose garden in Regent's Park where Pongo and Perdita met for the first time in Disney's "101 Dalmatians."

A museum wholly devoted to juvenescence.

More than a million titles fill the labyrinthine shelves of this prestigious private library.

The first tunnel to be dug beneath a river, repurposed as an art and museum space.

The first geometric self-supporting spiral stairs in Britain are a truly beautiful sight.

Colin Stokes "got a bit carried away" and built a castle that looks like something out of Tolkien.

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

This crumbling folly looks like an enchanted left over from Middle Earth.

These official units of measurement—including chains and perches—lie hidden beneath tourists' feet in a popular London hub.

The library houses an incredible collection of some of the world's most impressive books and manuscripts.

The forest that inspired Winnie-the-Pooh's Hundred Acre Wood can be found outside London.