Apartment complexes built into huge repurposed natural gas tanks.

Vienna's underworld of tunnels and subterranean rivers made an iconic appearance in a 1949 Orson Welles film.

The townhouse where the "Blood Countess" Elizabeth Báthory started her murderous career.

A silly medieval mural preserved on the side of a Viennese house.

The largest ice cave in the world is thought to be the entrance to hell according to Austrian legend.

This museum promotes informed contraception by documenting its often secret past.

Legends surround an ancient tree trunk riddled with nails for good luck.

An Austrian house of bones filled with hundreds of intricately painted skulls.

Artfully arranged bones of 5,800 Austrians.

A centuries old castle atop a dormant volcano houses museums devoted to both women and witches.

Each year melting snow turns these Austrian hiking trails into scuba zones.

This cubist Vienna church building looks like some sort of alien stonehenge.

The resting place for anonymous victims of the Danube's dark waters.

Located right outside of Vienna, visitors can take in expansive views of an ethereal forest.

The former private quarters and office of Dr. Sigmund Freud now hosts a museum housing the works of the founding father of psychoanalysis.

This Austrian museum celebrates the work of famous forgers and their inimitable imitations.

A spherical "micro-nation" in the heart of Vienna.

Handsomely crafted representations of our round planet.

Swarovski's museum/theme park is a fake diamond fantasia overlooked by a giant.

Macabre museum devoted to historical Viennese murders.

The final resting place for the remains of 143 Habsburg royalty.

The beautiful baroque library of the Hapsburg empire.

In memory of The Blur Building, the temporary exhibition pavilion of vaporous nothingness.

This large sculpture of white plates and forms is actually a huge sound amplifier.