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

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

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

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

This natural hill rose another 130 feet from the debris and rubble added after World War II.

Inside this discotheque resides a unique memorial dedicated to one club-goers favorite pet.

The remains of three Luftwaffe launch pads designed for manned anti-aircraft missiles.

Remnants of a cone-shaped Nazi bomb shelter.

An old slaughterhouse now holds the largest collection of pig artifacts.

This old wooden funicular railway leads to a cemetery in the forest.

A marvel of technology a century ago, this disused power station now offers a lovely glimpse into the industrial design of the past.

Beautiful antiques and obscure engineering artifacts trace the evolution of phones from rare luxuries to ubiquitous.

At this exhibit on the world of poison, venomous animals steal the show.

These 12th-century catacombs carved into a mountainside were a place of mysticism and Christian hermitages.

A small marionette collection located within the dark cellars of an 11th-century Austrian castle.

The amazing wonder cabinets of a very rich Austrian archbishop.

The medieval network of canals hidden underneath the city is opened to explorers each year.

Mozart's skull may be held in this collection, but definitive proof continues to elude scientists.

Ugly 18th-century dwarf statues living in a perfectly landscaped Austrian garden.

Terrifically morbid cemetary and site of famous Paracelsus' grave.

Trick water gardens from 1619 featuring a 200 piece mechanical theater powered by water.

This statue honors one of Budapest's most beloved literary characters.

The largest statue of this convex, homogeneous object with just one stable and one unstable equilibrium point.

A giant glider—designed by the father of the Rubik's Cube's designer—now soars within a shopping mall.