A wunderkammer of curious objects and intriguing art nestled within a hub of ancient Roman sites.

St. Francesca Romana, patron saint of drivers, resides in the church she founded.

One of the most important yet well-hidden museums dedicated to the history of medicine.

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

A hospital where antique dolls are given new life.

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

Jesus' footprints and the first catacombs in the world.

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

The underground sanctuary of a mysterious ancient cult.

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

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

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

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

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

One of the world's oldest olive trees, thought to be over 2,000 years old.

A curious little museum dedicated to the furry feline in the cat haven that is Old Town Kotor.

In this Parisian garden's grotesque former life as a zoo it fed exotic animals to the bourgeois and put humans on exhibit.

Abandoned railway line circling the city of Paris.

France's most famous cemetery, with some of its most curious tombs.

The macabre collection of Jacques Sirgent, an expert scholar on the undead and all of their trappings.

The vast, legendary catacombs hold secrets much stranger than stacked bones.