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

Inside this building is another country within Rome, a sovereign entity without a physical territory.

Architectural monsters are devouring this palace's every door and window.

Its interior is adorned with some of the best examples of early Christian mosaics.

Inside this McDonald's you can dine on your Big Mac and fries next to a 2,500-year-old Roman wall.

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

Ancient ruins hidden underneath a modern luxury hotel.

This ancient market is often referred to as the oldest shopping mall in the world.

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

Ever hear of the Milazzo Cage?

In Rome’s Jewish ghetto, a 200-year-old bakery still makes the neighborhood’s historic sweets.

The spot where the fascist dictator made some of his most famous speeches including declaring war on Britain and France.

The best preserved Paleochristian basilica in Rome hides a number of oddities and secrets.

This is the oldest Roman-made bridge in the city still existing in its original state.

In the early Roman Empire, people deemed traitors and criminals were tossed to their deaths from this rock.

These hut foundations are believed to be the residence of Romulus, founder of Rome.

The only remaining arch of the oldest stone bridge in Rome stands in the middle of the Tiber.

This one-of-a-kind Roman arch is not actually dedicated to the god Janus.

This small, ancient Roman temple was once a church dedicated to the patron saint of penitents.

This curious, round temple is the oldest still-standing marble building in Rome.

The remains of this 2nd-century Roman temple are incorporated into a modern building.

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

A stunning bridge that appears as if it's lunging to the shore, and has a legend of a devilish architect.

This enchanting 600-year-old tree is so magical it inspired the beloved tale of Pinocchio.