Eccentric concrete mansion and museum designed and built by hand from the inside out.

The Art Deco artwork depicts gilded carriers of deadly illnesses.

A closed London rail station created to cart away the dead still bears the marks of attempts to make it less morbid.

This open-air mosaic gallery honoring an English artist took hundreds of volunteers more than seven years to create.

A faded reminder of what was once a common sight in London during the Blitz.

Colorful murals by Jean Cocteau hide within this peaceful London sanctuary.

The lab where the scientist made his groundbreaking discoveries is preserved on the basement floor of the Faraday Museum.

The John Snow Memorial marks the epicenter of London's 1854 cholera epidemic.

This knockout museum lies in a sleepy corner of London.

A plaque marks the underground site of one of London's "lost rivers."

The "shampooer of kings" who opened London's first curry cafe was a celebrity in the 19th century, but is all but forgotten now.

It is still illegal to "quarrel" at this unlikely urban oasis built on top of an electrical substation.

This five-star hotel was originally a swanky parking garage.

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

This overlooked street light once served as a KGB dead letter box.

The canine-themed book collection claims to be Europe's largest dog library.

Some of the earliest leaders of the Moravian congregation are buried here.

A relic from one of London's worst 19th-century slums.

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

This museum inside a museum tells the story of London's timepieces.

A historic house left in "dramatic still life."

Home of one of history's most famous cartoonists just as he left it.

This ancient oak plays host to carvings of magical elves, gnomes, witches, and other creatures prominent in local folklore.

The dramatic remains of an abandoned farmhouse sit high on the edge of a remote hillside.