A mysterious chasm in the heart of the ancient Roman Forum, the Lacus Curtius was once believed to be a gateway to hell.

A complex, nine-layer maze on the grounds of a Venetian doge's playground.

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

The Pope’s secret escape route.

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

This immaculate and historic water garden culminates in a massive stone dining table with an inset fountain for chilling the wine of the Cardinal's guests.

Natural cathedral designed by Italian artist Giuliano Mauri.

Abandoned medieval hill town.

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

Crushed coral and crystals give the sand its signature coloration.

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

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

This enchanting 600-year-old tree is so magical it inspired the beloved tale of Pinocchio.

An Italian hillside ghost town.

Geothermal waterfalls in Tuscany.

According to the local folklore, the myriad colors of this lake are the result of a lovelorn wizard's blunder.

Stalactites and stalagmites in a beautifully lit cave.

The doodles of a genius line the walls of a secret room under the Medici Chapel, where they were hidden for nearly 500 years.

Rome's ancient Etruscan rival, now a park full of ruins.

A huge enchanting public park just outside the ancient walls of Rome.

The "Greatest Sewer" of ancient Rome is one of the oldest sewer systems in the world, and is still in use.

An Italian ghost town that fought obscurity, until a mysterious illness brought it to its knees.

This hill made entirely of ancient Roman jars was simply a garbage dump to the people of the time.

One of seven Jewish catacombs in Rome and one of only two open to the public.