A charming 17th-century alley is lined with secondhand bookstores and antiquarian shops.

The fences outside some of South London's estates are made from recycled World War II stretchers.

A collection of machines designed to break things for science.

One of the world's largest collections of pathological specimens.

This South London cemetery holds the remains of more than 15,000 people.

In this cobwebbed old operating theater, you can practically hear the screams of the unanesthetized patients.

A traditional American farmhouse plopped in the middle of a Piccadilly courtyard.

The collection contains over 25,000 items and details the painful dental practices of the past.

This knockout museum lies in a sleepy corner of London.

This informal museum is a magical trove of anonymous art collected from car boots and flea markets.

An underwater restaurant, surrounded by a coral reef.

Semaphore saints, a golden dragon's head, and a stone carved with religious warnings all call this cathedral home.

An incredibly well-preserved piece of ninth-century Viking poop.

Makers and sellers of the original and finest York Ghosts.

The remains of an ancient bathhouse sit inside this aptly-named pub.

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

The remains of 40,000 humans, meticulously stacked in a tiny churchyard shed.

This modern French ossuary contains the jumbled bones of 130,000 WWI soldiers.

A house of bones — but nobody is quite sure to whom they belong.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

Fantastically decorated underground chambers built in the 1760s.

The smallest pub in Britain was once a cabinet of curiosities and it still has the dead cat to prove it.

One of the largest mines in Bulgaria is now home to a vast museum more than 100 feet underground.

Overshadowed by other, more famous Maltese catacombs, this ancient burial chamber has one of the best examples of a ritual agape table.