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

Brass cobblestones mark the places where individual Holocaust victims were taken from their homes.

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

This sword isn't waiting for a king to pull it out. It was placed there by a saint.

Pilgrimage site for star-crossed lovers.

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

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

A Nesting Doll of Churches.

One of several skulls claiming to belong to the beheaded St. John the Baptist is on display at this Roman church.

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

Over 50 exquisite hand-painted Renaissance maps decorate a Medici storage room.

Go inside to really appreciate this 500-year-old technological masterpiece.

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

Jesus' footprints and the first catacombs in the world.

2300-year-old Roman road connecting the empire.

The skull of the patron saint of lovers lies in the Basilica di Santa Maria in Cosmedin—maybe.

The yawning maw of this pagan visage is said to bite off the hands of liars.

Rome’s legendary peephole vista is also a former Crusader stronghold.

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

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

The resting place for anonymous victims of the Danube's dark waters.

This fortress in Honduras was built to resist pirates, but its builders had more to fear from the British.

A full-size replica of this well-preserved temple lets you take a walk through the Mayan age.

This staircase full of Mayan hieroglyphics is perhaps the largest single text in the world.