The oldest stone house in Paris was built by its most famous alchemist.

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

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

A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.

A fascinating insight into daily life in the Eastern Bloc.

An abandoned NSA listening post on Berlin's "Devil's Mountain."

A slice of central Asia in the middle of Berlin.

Blitzkrieg bop your way through Berlin's Ramones Museum.

An eerie, existential museum dedicated to the author of "The Metamorphosis."

A bust of Franz Kafka spins in pieces, reflecting the writer's inner torment.

Buried five stories underground, this Soviet bunker is packed with gas masks and Cold War paraphernalia.

A collection of anatomical samples from one of the first anthropologists to suggest that humans reached North America by crossing the Bering Strait.

Small museum dedicated to one of the founding fathers of modern astronautics.

A Jenga-style cylindrical tower of books that appears to go on forever.

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

Macabre astrological automaton clock dating to the late 1400s.

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

Stuffed people arranged in unsettling scenes give a voyeuristic glimpse of life within a historic old hotel.

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

Two stunning 17th-century libraries and a cabinet of curiosities.

A Seattle oddities shop brimming with Victorian-era gems and antique curio.

Pick up all of the cosmic knick-knacks under the sun or take a creative writing course, all offered in this novelty storefront.

Hidden above a drug store on a nondescript corner of Lincoln Heights is a private clubhouse for intrepid explorers.

Space program, pneumatics and more, bits and pieces, for movie sets or the common man.