According to the legend, this structure was built in a single night with the help of the devil.

A series of caves, tunnels, and wells filled with fascinating figures and symbols.

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

This monumental fountain has moved around the city multiple times.

Believed to be the remains of the lost Temple of Minerva, this nymphaeum has been known by its misnomer to this day.

A medieval stronghold rising over the ruins of ancient Roman villas along Rome's southern coast.

This network of roads is one of the most unique Etruscan creations ever discovered.

This medieval mountain town is also known as the "Village of Streams."

For centuries, this large Roman villa remained hidden thanks to the eruption that buried nearby Pompeii and Herculaneum.

A stunning hermit's shrine on a steep rocky spur in Northern Italy.

A stunning medieval castle houses this eclectic, interactive tribute to all things wine.

An abandoned bell tower in the middle of nowhere is the last testimony of a forgotten medieval village.

The old church, buried by the 1784 Mount Vesuvius eruption, is a remarkably well-preserved place where people now pray for the souls of the dead.

A rare example of a medieval house in Rome adorned with a melancholic inscription.

Also known as the Temple of Poseidon, this is one of the best-preserved Greek temples in the world.

One of Rome's most picturesque and original bridges was also a popular choice for Grand Tour artists.

This elaborate hole in the ground was built as a sacred site for an ancient civilization.

A colossal aqueduct from the second century B.C., deeply hidden in a gorge on the outskirts of Rome.

Hidden in a high mountain cave, this hermitage dates back to the ninth century.

A secret hatch containing two parchments was discovered in this statue over 40 years after its installation.

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

Featuring the last fully walkable parapet walkway in Europe.

The “Sistine Chapel” of the Middle Ages merges 11th-century science and religion in wondrous hues.

The relics of dozens of martyrs are stored in a single chapel.