Stone memorial that's said to predict the death of the pope and the site of the Cadaver Synod.

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

Brass cobblestones mark the places where individual Holocaust victims were taken from their homes.

A treasure trove of Renaissance-era funerary art in a Roman church built on top of Nero's grave.

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

A lover's walk between hilltop towns, decorated with graffiti love notes.

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

This private skyway is filled with art and was expanded explicitly so that Hitler could appreciate a river.

Installed in an act of one-upsmanship, the annual sundial in this church is also a symbolic victory for the Gregorian calendar.

The famous sculptor left his mark on this Italian wall in an internationally protected example of street art.

This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

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

Five candy-colored villages on the Italian Riviera.

Architectural monsters are devouring this palace's every door and window.

A large grotto built in the 16th century amidst Florence's famous Boboli gardens.

2300-year-old Roman road connecting the empire.

The yawning maw of this pagan visage is said to bite off the hands of liars.

Rome's semi-secret peephole vista is also a former Crusader stronghold.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

This community on a small Venetian island has taken to painting their houses in bright neon hues.