This bustling Italian plaza is built on the ruins of an ancient Roman amphitheater.

This historic recreationist school churns out warriors that may very well have had a fighting chance in Rome's pits of the day.

An enigmatic modern marker left next to a historic Roman site.

The martyr's wax-enhanced skeletal remains lie preserved in a glass case in the Santa Maria della Vittoria in Rome.

The Pope’s secret escape route.

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

This delightful little museum is dedicated to only one thing: pasta.

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

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

Museum dedicated to literary greats of the Romantic Period is also the home in which Keats met his untimely end.

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

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

Charles Dickens was not a fan of the ghastly wall dressings in this 6th century church.

A Nesting Doll of Churches.

A collection of objects supposedly singed by the hands of souls in purgatory.

2300-year-old Roman road connecting the empire.

The underground sanctuary of a mysterious ancient cult.

An alchemist's "magic door" stands in the middle of a Roman park.

This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

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

One of the Cemestos prefab homes built to secretly house thousands of Manhattan Project workers.

This 6th-century church has the largest and best-preserved collection of Byzantine mosaics outside Constantinople.

The roof of this ancient mausoleum is made from a single Istrian stone weighing a massive 230 tons.