The first modernist church in Europe.

Visiting this café is like visiting the Austrian grandma you wish you had.

An ornate private entrance to the Vienna subway built specifically for the emperor.

The housing complex served as an anti-fascist fortress during the Austrian Civil War.

This grand manse has been transformed into a museum devoted to one of the founders of Fantastic Realism.

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

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

An exquisite Baroque church in Vienna's old town.

Trick water gardens from 1619 featuring a 200 piece mechanical theater powered by water.

Dine amidst exotic plants at this former royal greenhouse.

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

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

Before it was buried by volcanic ash, this fast-food restaurant fed the hungry hordes of ancient Rome.

This clifftop arch is a natural stunner.

This one-of-a-kind Roman arch is not actually dedicated to the god Janus.

Two stone columns flank the grand Venice square, but there were supposed to be three.

This curious, round temple is the oldest still-standing marble building in Rome.

The walls and streets of the ancient city are peppered with penises.

An extensive collection of reliquaries containing the bones of saints housed in the largest Catholic church in Venice.

Thousand-year-old Viking runes adorn an ancient Greek lion at the entrance to the Venetian Arsenal.

Venice's island of the dead.

A mysterious chasm in the heart of the ancient Roman Forum, the Lacus Curtius was once believed to be a gateway to hell.

This palatial spiral staircase was so unusual the name "snail" was given to the noble family who built it.

Go inside to really appreciate this 500-year-old technological masterpiece.