A steampunk-styled three-floor factory churning out art, activism, and electronic beats.

Countless grotesque faces stare out from this eerie Prague art wall.

The hidden lair of an alchemist rediscovered in a 2002 flood.

The history of occult science is turned into a creepshow at this lurid Prague tourist attraction.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

A psychedelic labyrinth on the San Francisco bay.

Micro-nation based around a nine-story high illegally built tower.

This Polish cave has housed a dragon, a brothel, and an enduring legend.

Giant, pink stuffed rabbit on an Italian mountain.

Hidden in an Italian forest is a completely homemade amusement park that has taken a lifetime to create.

Stalactites and stalagmites in a beautifully lit cave.

A 16th-century horror show built in a lovely Italian garden.

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

A grotto-like lodge decorated with gilded mosaics, rocks and a noisy waterfall was the setting for the most sumptuous pleasure house of 1900s Europe.

The macabre collection of Jacques Sirgent, an expert scholar on the undead and all of their trappings.

This subterranean disco dance club in a Cuban cave comes with bright lights and a dark legend.

This bizarre English competition answers the important question: how many worms can YOU coax out of the ground?

The photographs of "fairies" that fooled much of the world (including the creator of Sherlock Homes) were taken at this English stream.

A 26-foot shark sculpture—a statement about bombs—set off a municipal battle royale.

A 200-year-old prison that now houses a peculiar crime museum.

Museum about life, death, and cannibalism in the Stone Age.

A modern English garden of eccentric beasts, follies, and oddities.

400-year-old garden, restored to beauty.

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