Mary Kelly was last seen here before she was murdered by Jack the Ripper.

Dictionary Johnson’s favorite feline.

A tongue-in-cheek arcade where the games are based on everyday life.

This shop and gallery is a modern-day cabinet of curiosities, unassumingly positioned along an urban thoroughfare.

A kaleidoscopic warehouse-maze of handmade neon signs.

Jesus' footprints and the first catacombs in the world.

Rome's semi-secret peephole vista is also a former Crusader stronghold.

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

The underground sanctuary of a mysterious ancient cult.

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

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

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

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

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

At the crypt of St. Mary of Eulogies and the Dead you are left alone to ponder mortality among piles of skulls.

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

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

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

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.

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

This former Roman Catholic Church still contains the embalmed hearts and organs of 22 popes.