Suffocating dogs was a common spectacle in the fumes of this noxious cave.

A long-buried ancient ruin unearthed right in the middle of the city.

Skulls and skeletons are omnipresent in this church dedicated to souls trapped in purgatory.

The sunlight passing through the opening of this huge cave system creates a magical effect.

Why a column on the entrance is inscribed with a verse from the Quran is one of Sicily's many mysteries.

This amazingly well-preserved villa just outside Pompeii boasts rare examples of ancient Roman paintings.

Italy's third-largest Roman arena gives a peek into the underground operations beneath the ancient spectacles.

This triumphal 16th-century arched gateway leads to the oldest street in Palermo.

The remains of the left arm of the levitating philosopher-saint are kept in a 13th-century Neapolitan basilica.

A medieval wash house where people washed clothes in a river allegedly formed by the tears of a mourning nymph.

An abandoned quarry hides an open-air gallery of huge sculptures, some made from the rubble of 9/11.

Thousand-year-old Viking runes adorn an ancient Greek lion at the entrance to the Venetian Arsenal.

The walls and streets of the ancient city are peppered with penises.

The only visible reminders of an elaborate engineering project that kept the tower from reaching the tipping point.

The underground sanctuary of a mysterious ancient Roman religious cult contains an exquisite traditional fresco.

A dead saint, a deadly poison, and a mysterious holy ooze.

A tree that defies gravity grows in an ancient ruin.

Haunting graffiti left by prisoners of the Spanish Inquisition.

This Arabesque Italian castle was built with a primitive, if ingenious, air-conditioning system.

The steel cable lets adventurers zoom between two mountain towns at speeds of up to 75 miles per hour.

Those who own or stay at this 500-year-old, allegedly cursed house often meet terrible fates.

Two stone columns flank the grand Venice square, but there were supposed to be three.

Behind medieval walls in a corner of bustling Palermo is a breathtaking former mosque once inhabited by a wolf-taming hermit.

Every inch of this chapel is covered in craftsmanship from across the world.