This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

Housed in an old church, this hunting museum holds a collection of mythical bird-rabbit creatures.

This shop and gallery is a modern-day cabinet of curiosities, unassumingly positioned along an urban thoroughfare.

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

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

A museum dedicated to a secret military hospital hidden beneath a castle in Budapest.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

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

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

This beloved marketplace mascot poops money and grants good luck.

A daily replay of the experiment that proved the rotation of the Earth.

A tiny museum housed in a New York freight elevator specializes in the "overlooked, dismissed, or ignored."

A terrific purveyor of natural history objects and curios.

"I did this all while you were watching TV."

The official atomic museum of the United States explores the explosive and productive history of a much maligned energy source.

A museum devoted entirely to the rattlesnakes and snake-related art.

See massive fossils that are over 200 million years old in northeastern Arizona.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

A stealthy Apache hideaway that became the haunting site of a mass grave.

The story of Two Guns, Arizona could easily be described as a Shakespearian tragedy on Route 66.

The final resting place of the businessman-turned-astronomer who helped discover Pluto stands near his observatory.

This Arizona observatory is famous for investigations into Martian life, and as the place humans first spotted Pluto.

A planet-hunting astrograph built in the 1920s to seek out the so-called "Planet X" beyond Uranus.

An important piece of history from mankind's journey to the moon sits in the lobby of a government science lab.