This massive subterranean fissure is known as the "underground Grand Canyon."

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

An island on the Venetian Lagoon hosts this stone chair that has nothing to do with the King of the Huns.

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

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

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

This uniquely designed bridge served as the city gate for Comacchio.

Stuck in the arcade of Casa Isolani are three arrows of mysterious origins.

Over 100 towers were built in Bologna during the Middle Ages, but only 22 survive.

Legend has it this fountain built to symbolize the Pope’s power hides a strange secret concerning Neptune's manliness.

The graveyard is filled with beautiful funerary art and boasts breathtaking views of Florence.

A copy of the famous statue can be found in this Florence piazza, along with one of the most breathtaking views of the city below.

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

A stunning bridge that appears as if it's lunging to the shore, and has a legend of a devilish architect.

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

Although called a funicular by both its owner and the locals this historic railroad is actually a rack and pinion system.

Massive galleon from a box-office bomb docked in Genoa.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

Stockholm's deepest subway station is also a stunning ecological wonder.

Stockholm's tiniest statue is of a small boy looking at the Moon.

Stockholm's narrowest alley is barely over two feet wide.

A plaque marks the house in Stockholm where the French philosopher René Descartes lived up until his death.

The Swedish flag over this small naval fort signals that the nation is at peace.

Sweden's oldest animated sign is still lighting up the skyline today.