This 6th-century church has the largest and best-preserved collection of Byzantine mosaics outside Constantinople.

Italian poet Dante Alighieri is entombed in this small mausoleum in Ravenna, and his hometown of Florence has never been too happy about it.

The entire known universe of the ancient Etruscans is held inside this bronze model of a sheep’s liver.

The tomb of history's greatest potato promoter is surrounded by tubers.

The final resting place of the "father of special effects."

The sunken structure looks like the victim of a catastrophic flood.

This tiny hotel perched atop a 50-foot tower really puts things into perspective.

These red marks, seemingly placed at random, are in fact not.

This banal Parisian entranceway is not what it seems.

Apartment complexes built into huge repurposed natural gas tanks.

The famous winding walk at Chartres is surrounded in mystery and myth.

This bustling Italian plaza is built on the ruins of an ancient Roman amphitheater.

The mark of the Devil's horns on a marble column in Milan.

In Florence's great Duomo, a 26 foot fresco honors a mercenary famous for attacking Florence.

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

The oldest operating pharmacy in the world features 800-year-old recipes.

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

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

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

A new sculpture calls attention to climate change in the centuries-old city it threatens.

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

A French artist's vague warning hangs over Belleville.

This church sits upon a peaceful hill and a long, turbulent history.

Beggars were miraculously "cured" of their fake ailments when they returned home to this 17th century Paris slum each night.