The engineering wonder and pleasure dome of a much-maligned emperor still holds undiscovered secrets.

The ruins of the largest gladiatorial school in Rome are largely hidden under modern streets.

An unremarkable wooden wheel built into the side of one of Rome's oldest hospitals was part of a policy to reduce infant exposure.

Stone memorial that's said to predict the death of the pope and the site of the Cadaver Synod.

According to local folklore, this Roman sepulcher was once a throne for the Devil.

A monumental fountain in Rome features a large statue of Moses that has been criticized for centuries.

A modern sliver of architecture in Roma.

This hydrochronometer was invented by a Dominican monk and is a prime feature in this garden.

Gods clash with machines in a power plant regenerated as a museum.

This bronze boar's snout has been rubbed to a golden sheen by visitors seeking good fortune.

Some say this medieval church is where the poet Dante married his wife and also met the love of his life.

The oldest operating pharmacy in the world features 800-year-old recipes.

Memorials at a Florence railway station remember the citizens who were deported from Italy and sent to extermination camps.

A slightly creepy gallery of plaster cast models in the same museum as Michelangelo's David.

Fountain where visitors can earn a license to be mad.

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

An unusual house built using an iso-elastic membrane.

The giant skeleton sculpture is surprisingly well-traveled.

A lavish 16th-century mansion filled with spectacular staircases, fantastic frescoes, and gorgeous gardens.

A 17th-century doorway in a small Sabine village is a portal into the mysteries of alchemy.

This ancient Roman bridge was a key feature of the ancient Via Salaria road.

When occupying Nazi troops detonated a mine below, medieval frescoes were revealed in this small cliff-side hermitage.

This beautiful Romanesque church preserves stunning medieval frescoes and the excavations of a Roman market town.

Hidden within this iconic mountain are a set of World War II bunkers once used by German forces.