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

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

Also known as the Square Colosseum, this building is a prime example of fascist-era rationalist architecture.

The ruins of an abbey believed to have been founded by Charlemagne in the 9th century.

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

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

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

A detailed pachyderm supports Rome's smallest Egyptian obelisk.

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

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

Ancient ruins hidden underneath a modern luxury hotel.

A magnificent waterfall is also home to the remains of a Roman hydraulic engineering system.

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

A treasure trove of Renaissance-era funerary art in a Roman church built on top of Nero's grave.

A huge enchanting public park just outside the ancient walls of Rome.

An Italian ghost town that fought obscurity, until a mysterious illness brought it to its knees.

This large, circular tomb is the final resting place of the first emperor of Rome.

This hill made entirely of ancient Roman jars was simply a garbage dump to the people of the time.

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

A mysterious chasm in the heart of the ancient Roman Forum, the Lacus Curtius was once believed to be a gateway to hell.

This ancient Roman prison is decorated with an upside-down cross not as blasphemy but as saintly tribute.

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

This Roman arch marks the location of an ancient gate at one of the Seven Hills of Rome.

Installed in an act of one-upsmanship, the annual sundial in this church is also a symbolic victory for the Gregorian calendar.