The world's only museum devoted to the wonders of fluorescence.

An immersive environment that is part haunted house, part choose-your-own-adventure, and part jungle gym.

The fairy tale castle of the "fairy-tale king."

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

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

Tucked in the back of this amazing antique store is an important piece of medical history.

World's first "penitentiary," meant to be humane, drove men insane.

This iconic L.A. bookshop is housed in an abandoned bank—both symbolic and chic.

A psychedelic labyrinth on the San Francisco bay.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

World's largest collection of serial killer artwork and other macabre exhibits.

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

A terrific purveyor of natural history objects and curios.

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

This weird abode has inspired everything from the "House On Haunted Hil" to a robot hunter's pad.

Nancy Thompson's Home from "A Nightmare on Elm Street."

The site of a tragic massacre that spawned a multimedia franchise.

Artfully arranged bones of 5,800 Austrians.

The walls and ceiling of this Polish church are decorated with thousands of skulls, with another 21,000 skeletons just below.

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

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

A church of bones, decorated with 40,000 human skeletons.

A particularly creepy abandoned hospital that sparks interest for lovers of the supernatural.