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

Pilgrimage site for star-crossed lovers.

Dug as a secret royal escape route, the tunnel became a wartime bomb shelter and dumping ground for vintage cars.

In Rome’s Jewish ghetto, a 200-year-old bakery still makes the neighborhood’s historic sweets.

The Pope’s secret escape route.

A forgotten "city of water" underneath the famous Trevi district.

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

The abandoned "Ghost Mansion" was left to decay in the mountains of Northern Italy.

This palatial spiral staircase was so unusual the name "snail" was given to the noble family who built it.

Crushed coral and crystals give the sand its signature coloration.

This 16th-century monastery has been turned into a surrealist architecture compound.

A collection of objects supposedly singed by the hands of souls in purgatory.

One of the world’s smallest bars, just 13 square feet, is brimming with speakeasy flair.

This centuries-old Italian chapel hangs midway down a sheer cliffside.

Five candy-colored villages on the Italian Riviera.

An Italian hillside ghost town.

This quaint Italian town keeps losing ground as the sides of its plateau slowly erode.

Hidden in an Italian forest is a completely homemade amusement park that has taken a lifetime to create.

This giant middle finger statue sends an unambiguous message to Italy's bankers.

The largest and most famous wax anatomical collection anywhere in the world.

A Milanese café entirely designed by the American director Wes Anderson.

Jesus' footprints and the first catacombs in the world.

A labyrinth of ancient tunnels hidden below the city holds the ruins of 2,500 years of history.

The glowing blue Nymphaeum of Emperor Tiberius.