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

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

This Roman statue is missing a limb from when the Venetians stole it from Constantinople during the Crusades.

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

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

This strange bovine gargoyle is said to have been put in as a passive aggressive form of revenge.

This bronze boar's snout has been rubbed to a golden sheen by visitors seeking good fortune.

Milan's duomo is covered in beautiful carving including a curious "dinosaur-like" beast.

This equestrian statue of Constantine the Great has been the subject of criticism for centuries.

Historic fortifications form the boundary of Vatican City, but it’s not entirely surrounded by walls.

This is the oldest Roman-made bridge in the city still existing in its original state.

The only visible reminders of an elaborate engineering project that kept the tower from reaching the tipping point.

Next to the Leaning Tower of Pisa is a cemetery home to ancient sarcophagi and disturbing murals.

This ancient theater was once the home of fierce gladiatorial battles.

In one of the smallest countries in the world stands an original Salvador Dalí sculpture.

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

A vista of the city and sea from atop the little-known viewing deck on an unassuming Columbus statue.

An eerie collection of the surviving structures from a past celebration of the future.

This 19th-century fountain's namesake animal isn't what you think it is.

This castle has links to Portugal’s founding and struggles for independence.

A stunning 18th-century site where pilgrims ascend by a series of punishing stairs only to return via funicular.

The "Little Ones," show Portugal in full miniature splendor.

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.