This home on a quiet suburban street is completely covered with vibrant mosaics.

The sanctuary seems to either float atop the water or sink into the dirt, depending on the water level.

"The Donut" was built as part of an expensive, ill-fated engineering endeavor.

Under a church hides a forgotten 13th-century ossuary containing the remains of around 2,500 people.

The longest and steepest staircase locks in the United Kingdom.

An intriguing three-sided folly is a testament to one man's devotion to Catholicism and the number three.

Hundreds of huge, centuries-old horseshoes adorn the walls of this nontraditional 12th-century castle.

The Art Deco artwork depicts gilded carriers of deadly illnesses.

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

The British monarchy's stamp collection is one of the most impressive in all of Europe revealing generations of royal nerdery.

The world's oldest optical museum is an odd collection where the exhibits look at you.

This former medical factory gives home to cutting edge arts in the shadow of a gas works.

A little slice of Japan and its aesthetics in London's Holland Park.

The Columbia Road Flower Market is now open every Sunday, rain or shine.

19th-century scientists would make the pilgrimage here to verify the precision of their measuring sticks.

The monster at the center of the Darwin Center Spirit Collection.

A toy store with a century-long history preserves the craftsmanship of playthings of the past.

A cluttered and astounding collection of antiquities and curiosities.

The world's first underground farm is in a World War II bomb shelter beneath the streets of London.

Several plaster noses are hidden in plain sight around London's Soho neighborhood.

A subterranean ice warehouse that has lain hidden beneath central London for over a century is now open to the public.

Horsemen once used this tilting post during jousting practice.

The largest and most famous wax anatomical collection anywhere in the world.

The only remaining collection of flayed figures made by French "madman" Honoré Fragonard.