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

The personal charnel house of Anton Bruckner.

"World machine" built by an untrained Austrian farmer.

A rooftop restaurant hides in plain sight atop Vienna's Palace of Justice.

Visitors dip into a variety of pools of what was once ice.

Double spiral staircases are not unheard of, but they are very rare.

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

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

Artfully arranged bones of 5,800 Austrians.

Baroque celebration of the end of the Great Plague of Vienna.

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

Terrifically morbid cemetary and site of famous Paracelsus' grave.

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

Op-art architecture designed for happiness.

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

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

This former insane asylum now holds a pathological anatomy museum.

Built to give thanks for the passing of a plague epidemic, this cathedral is a one-of-a-kind architectural hybrid.

The crypt of the imposing Stephensdom holds royal intestines and thousands of skeletons.

The world's largest squirrel statue clutches a pecan bigger than your head.

One of the best collections of wax anatomical models in the world.

The house that took a plunge into the facade of a museum.

The Habsburgs' royal collections of art and wonders.

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