At night, bats patrol this magnificent 18th-century space in search of book-eating pests.

A perfectly circular lake is formed by the crater of an ancient underwater volcano.

A series of abstract, silly sculptures represent the works of a great modern classical composer.

Established in 1638 to battle the Black Death, Hortus Botanicus Amsterdam is a treasure trove of rare flora.

The oldest stone house in Paris was built by its most famous alchemist.

This shining multicolored metro station deep under Naples is said to be the most beautiful in Europe.

The one-time watch house for incoming ships at the Golden Gate now stands abandoned and hidden in trees.

Gigantic mosaic sculptures of the figures on Tarot cards fill this colorful Tuscan garden.

This stunning French estate was so lavish that it landed its original owner in jail for the rest of his life.

An unusual sand beach in the middle of a forest.

Jean Tinguely's bizarre monster sculpture is hidden deep in a forest.

A statue commemorate Tommie Smith and John Carlos's brave protest at the 1968 Olympics, a watershed moment for civil rights.

The remains of what was, not so long ago, the world's largest city.

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

This subterranean shrine beneath a bike rental store celebrates the iconic Italian scooter.

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

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

A cave in southern Italy adorned with thousand-year-old Biblical frescoes existed in obscurity until fairly recently.

People have been living in the cave houses on this Italian hillside since the Neolithic era.

The Roman Emperor's lost summer home and grotto full of enormous sculptures sit along the Italian seashore.

The studio built by fascists in the hopes of "reviving the film industry" with the occasional propaganda film opportunity thrown in.

Ancient snack bar of the Roman Empire re-opened.

Crushed coral and crystals give the sand its signature coloration.

Ruins of a 10th century church tucked away deep in a botanical garden.