This Tuscan lake hides a 13th century town that is still visible when the water recedes.

This picturesque Umbrian city has a subterranean side that has long remained hidden.

Italian cave with exceptional acoustics and an unsavory history.

The bomb-ravaged remains of of a colossal Neptune.

"Stairs of the Turks", a chalky white cliff eroded conveniently into stairs, allowing for easy pillaging.

The location of the last witch trials of Italy, known as "The Salem of Europe."

One of the largest caves in the world open to the public.

This Italian foot path winds through the mountains via 52 individual tunnels.

Filled with goldfish swimming in a shallow pool of sea water, this ancient crypt is more wishing well than burial site.

This domed temple was built in a hidden cave mouth as a refuge for sinners seeking absolution.

An Italian hillside ghost town.

Stalactites and stalagmites in a beautifully lit cave.

A small island less than half a mile from Venice is a forbidden island with a dark and twisted past.

Bloodstains can still be seen in this medieval church where two medics saved lives on D-Day.