Earth's rocky history has rarely glittered so brightly as it does in this Spanish museum.

Abandoned for decades, trains still pass through the now-restored remains of one of Madrid's first metro stations.

Mysterious Spanish catacombs of unknown origins.

A modernist church in an ancient village.

An abandoned socialist utopia built in the late 19th century.

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

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

This museum tucked below a charming cafe gives a brief snapshot of photographic history.

The last four extravagant street signs of London's historic banking street.

Three small rooms at the back of the “official” church of London's clowns.

Taxidermied animals galore, by appointment only.

A hidden treasure in London with a rich medieval history, and the resting place of many luminaries.

This small museum in a former church crypt contains artifacts of the Elephant Man, Jack the Ripper and Florence Nightingale.

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

Repository for more than 22 million pickled specimens.

A collection dedicated to the treatment of disease, held in London's oldest hospital.

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

A historic London cemetery now serves as a nature park incorporating gravestones & memorial statues.

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.

A mysterious artist-run cabinet of curiosities and library.

Remnants of a Victorian garden feature sitting in public woodland.

A historic house left in "dramatic still life."

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