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

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

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

The shell of a medieval fortress offers commanding views of the area it once protected.

The solemn exterior conceals an opulent interior of this 17th century church.

The amazing wonder cabinets of a very rich Austrian archbishop.

A neo-Gothic church built to thank God for saving the Emperor of Austria from an assassination.

An exquisite Baroque church in Vienna's old town.

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

The personal charnel house of Anton Bruckner.

The world's oldest known salt mine.

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

The Habsburgs' royal collections of art and wonders.

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

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

Beautiful Austrian natural history museum with carved ceilings and row after row of ancient taxidermy.

Op-art architecture designed for happiness.

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

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

Artfully arranged bones of 5,800 Austrians.

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

Terrifically morbid cemetary and site of famous Paracelsus' grave.

The topiary maze at the Habsburg hunting lodge.

This former insane asylum now holds a pathological anatomy museum.