This 14th century castle withstood years of battle but is now sliding off the hills into the Danube.

Imperial palace of Emperor Galerius, the Emperor behind the worst Christian persecutions during the Roman Empire.

Two nations form a rare four-sided border at the peak of a mountain, philosophical questions result.

This spire on an Austrian mountain is wrapped around a long spiral slide and has the world's tallest wooden observation deck.

Part ski resort, part modern art space, this lodge brings giant metal spiders and bloody doors to the Austrian Alps.

American soldiers discovered Europe's best one-liner at the end of World War II.

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

Where beer lovers can literally immerse themselves in beer.

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

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

Giant WWII fortresses that fired 8,000 rounds a minute, now home to thousands of pigeons.

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

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

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

A tropical paradise just a short trip from the opera house is filled with beautiful winged creatures.

Museum devoted to the artificial language of Esperanto.

Handsomely crafted representations of our round planet.

Dine amidst exotic plants at this former royal greenhouse.

The beautiful baroque library of the Hapsburg empire.

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

A small museum filled with over 1,000 clocks, and one particular clock calibrated to run until the year 9999.

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

An exquisite Baroque church in Vienna's old town.

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