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

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

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

The Pope’s secret escape route.

If you want to talk to the Pope you will have to stare down this surreal vision of Jesus rising from a nuclear hell.

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

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

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

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

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

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

Jesus' footprints and the first catacombs in the world.

Hidden beneath the famous St. Peter's Basilica is a veritable city of the dead that may hold the remains of St. Peter himself.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

Rome's semi-secret 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.

Architectureal fantasy quarter of Rome.

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

A controversial artwork draws attention to the dark history of Prague's "Suicide Bridge."

The oldest garden in Prague, once part of an medieval orchard.

A former squatter's paradise outside Prague.

An Orwellian sculpture with eyeball cameras watches passersby.

A steampunk-styled three-floor factory churning out art, activism, and electronic beats.

An eerie, existential museum dedicated to the author of "The Metamorphosis."