Countless grotesque faces stare out from this eerie Prague art wall.

A Jenga-style cylindrical tower of books that appears to go on forever.

Two stunning 17th-century libraries and a cabinet of curiosities.

Stare out over the lagoon and beyond from this 10th-century campanile on the island where the city of Venice began.

Where Venice's gondolas go for a tune-up.

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

Originally a leper colony, the island is now an Armenian monastery that's home to an incredible manuscript library and eclectic museum.

The small peaceful island off the Venice tourist circuit is where the city began more than 1,500 years ago.

This abandoned island off the Venetian coast has been a radical monastery, a political prison, and a secret Nazi base.

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

Venice's island of the dead.

Hanging within this medieval church are the bones of a beast allegedly slain by a fourth-century saint.

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

Armenian monks at an island monastery in the Venetian Lagoon make a rare rose petal jam.

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.

As can be expected from a centuries old church built in a canal city, the undercroft of this house of worship is beautifully flooded.

This Venice bookstore has resigned itself to constant flooding by keeping its books in bathtubs and boats.

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

An exquisite Baroque church in Vienna's old town.

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

A museum capturing one of the world's most famous classical composer's battle with hearing loss.

A non-stop elevator ride in Vienna's city hall.

A gift from Emperor Franz Joseph I to his wife.