A small island in Lake Garda that was used as a burial site, pirate hideout, and a monastery.

An abandoned monastery sits on a far-off island in the Adriatic Sea.

An abandoned village, frozen in time by the threat of a landslide.

Hidden within this iconic mountain are a set of World War II bunkers once used by German forces.

This Torino museum honors a soldier who kept the city safe using barrels of exploding gunpowder, losing his life in the process.

This Roman underground canal was the longest tunnel ever built until the late 19th-century.

These artificial caves crafted by ancient Romans were elaborate fish farms for moray eels.

A burial vault located under Tiber Island in the middle of the Italian capital.

A series of caves, tunnels, and wells filled with fascinating figures and symbols.

This enormous sinkhole hides a secret world created from divine wrath.

With its mine closed, this old village is starting to resemble a ghost town.

Roman politician Herodes Atticus built this nymphaeum to honor his wife, whom he may have murdered.

Was this cave created by Hercules's wrath, the devil, or volcanic activity?

Contrary to what its name suggests, you won't find any bunnies here.

The marshy karst plain has reclaimed this beautiful 17th-century church.

This small but lovely sinkhole lake is the last remnant of a great prehistoric water basin.

Built to be the ideal penitentiary, this abandoned panopticon saw several revolts and even a prisoners' coup.

A massive mausoleum towers over the gravestones in a 19th-century Italian "model village."

Suffocating dogs was a common spectacle in the fumes of this noxious cave.

The pristine waters crossing this forest form a hidden waterfall among the dense vegetation.

Hidden in a high mountain cave, this hermitage dates back to the ninth century.

Italy's third-largest Roman arena gives a peek into the underground operations beneath the ancient spectacles.

On the shores of Lake Garda, the ruins of a Roman villa that allegedly belonged to the poet Catullus.

The old church, buried by the 1784 Mount Vesuvius eruption, is a remarkably well-preserved place where people now pray for the souls of the dead.