A 19th century artistocrat's mansion, turned into a library, hidden in a modern library.

Archduke Ferdinand II's collection of rare objects is considered one of the oldest museums in the world.

This splendid tomb may look fantastic, but there's nothing in it...

A pyramid in Central Europe of unknown origin.

The world's largest historic armory was established by independent citizens to defend themselves from the wars of larger forces.

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

An exquisite Baroque church in Vienna's old town.

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

This skeleton-filled altar piece served as a backdrop to one of the most iconic scenes in "The Sound of Music."

Austria's ultra-modern art museum looks like Cthulhu's giant alien heart.

Resting in the middle of an Austrian river, this sci-fi "island" lets people cross in neon style.

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

The amazing wonder cabinets of a very rich Austrian archbishop.

The world's oldest known salt mine.

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

Collection dedicated to funeral rites, equipment, and mourning rituals of the Viennese.

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

The personal charnel house of Anton Bruckner.

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

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

This series of underground chambers contains Europe's largest subterranean lake that is slowly drained each day.

The Habsburgs' royal collections of art and wonders.

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

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