Holy Grotto of Montserrat Monastery holds one of Europe's mysterious black Madonnas.

Mine shafts and hard pastries await visitors at this massive mountain of salt.

A cluttered and astounding collection of antiquities and curiosities.

London's smallest police station is barely the size of a phone booth.

Eighty million natural history specimens call this gargantuan museum home.

An alleyway plaque is all that remains of the independent Texas' envoy that forgot to pay their rent for over a century.

The anatomical-pathological collection of a man who changed surgery.

Catacombs turned marketplace.

A historic house left in "dramatic still life."

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

Hear the quietest sound from across the dome.

The quaint little store that is said to have inspired a famous Dickens novel was only given its name after the book was released.

The curios of pharmacist and collector Henry Wellcome.

The only university zoological museum in London houses extinct animals, bizarre natural history specimens, and a Micrarium of microscopic creatures.

An easily overlooked stretch of ornate window fronts and gaslight lamps that could be right from the pages of Dickens.

The perfectly preserved underground rooms where Churchill plotted the war against Germany.

Hidden beneath the streets of London is a secret subway that only carried mail.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

The remains of Crystal Palace Great Exhibition of 1851.

A Victorian natural history and ethnographic museum with wonderful turn-of-the-century, science-book-esque evolution displays.