A lover's walk between hilltop towns, decorated with graffiti love notes.

Ancient snack bar of the Roman Empire re-opened.

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

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

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

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

Dramatic sea stacks adorn the coast of this small village on the Adriatic coast.

The Sighignola summit on the Swiss border offers views so breathtaking it's been named one of the most beautiful places in Italy.

Pilgrimage site for star-crossed lovers.

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

The Pope’s secret escape route.

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

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

Over 50 exquisite hand-painted Renaissance maps decorate a Medici storage room.

Go inside to really appreciate this 500-year-old technological masterpiece.

Five candy-colored villages on the Italian Riviera.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

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

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

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

This hidden Art Nouveau courtyard is an opulent feast for the eyes.

This red light district plaza memorializes the Fab Four and their historic connection to the area.

Before he was forced to flee the country under Nazi rule, Albert Einstein spent his summers in this custom-built lakeside house near Berlin.

This Late Gothic building that once housed Erasmus is now known as the filming location of "Suspiria."