This mosaic-lined medieval church was built by the world's first admiral and still holds mass in ancient Greek.

Italian cave with exceptional acoustics and an unsavory history.

Venice's island of the dead.

Long-abandoned art nouveau baths beneath Milan's Piazza Oberdan.

One of the most important yet well-hidden museums dedicated to the history of medicine.

Ancient snack bar of the Roman Empire re-opened.

Erotic art covers the walls of the largest ancient pleasure palace.

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

An ancient artistic garden parlor full of hidden water wonders.

The sinister ruins of one of the worst dam failures of the 20th century lie in this astonishing alpine setting.

The Roman Emperor's lost summer home and grotto full of enormous sculptures sit along the Italian seashore.

This magical-looking island is notorious for the misfortunes suffered by its owners.

Walk through a fairytale in Tuscany.

This winding road through an Italian canyon may be the most scenic drive in the world.

Gigantic mosaic sculptures of the figures on Tarot cards fill this colorful Tuscan garden.

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

Crossing this suspension bridge feels like walking through the sky, a fitting tribute to the head of the Apollo program.

Secret refuge and museum of the Duke of Florence.

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

More sculpture than building, this architecturally significant temple was built on the spot of Saint Peter's crucifixion.

Romans built the world's tallest artificial waterfall in 271 BC.

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

A sunken idol welcomes parishioners to Davy Jones' Locker.

This abandoned Brutalist treehouse is a hidden architectural relic.