The underground sanctuary of a mysterious ancient Roman religious cult contains an exquisite traditional fresco.

This breathtaking monastery was established by Saint Benedict himself 1,500 years ago.

A mushroom-shaped outcropping that has come to be the symbol for an entire town.

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

Beautiful views and Roman-style statues on the Italian coast.

For centuries, this large Roman villa remained hidden thanks to the eruption that buried nearby Pompeii and Herculaneum.

This tiny islet has somehow housed an ancient temple, two monasteries, a church, a fortress, and a restaurant.

The oldest volcanology research center in the world.

This magical-looking island is notorious for the misfortunes suffered by its owners.

A sulfuric hellscape in southern Italy.

The Bourbon royal family had this unique octagonal hunting "cottage" built on a tiny islet in Lake Fusaro.

A steamer run aground near Bimini lives a second life as a playground for scuba divers.

This iconic fortress was once the crown jewel of Haiti's national defense.

The royal seat of Henri Christophe, a formerly enslaved man who became Haiti's only king.

Swim or sail to this pie-slinging boat off the coast of St. Thomas.

A mountain of conch shells created by centuries of fishermen.

This huge pile of volcanic boulders hides a stunning network of secret grottoes.

These eclectic homes nestled into the cliffs of a Caribbean island were built entirely from scavenged materials.

Starting with nothing more than discarded conch shells, one man has built an island/bar that would make Jimmy Buffet jealous.

A violent name for a violent volcano.

A gallery of underwater art that can be visited by man and fish alike.

The fishing boats that moor in this small lagoon enter and leave through a tunnel to the sea.

A mysterious ancient elephant said to possess magic powers is now the symbol of a Sicilian city.

This engineering marvel is the longest bridge in Canada and one of the longest spans in the world.