Historical figures from New York City's Catholic community reside in Midtown.

The mummified relics of an American missionary.

Cryptic messages embedded in the New York City sidewalk.

A tiny museum housed in a New York freight elevator specializes in the "overlooked, dismissed, or ignored."

Tucked in the back of this amazing antique store is an important piece of medical history.

A fortified medieval basilica on the Caelian Hill preserves extraordinary frescoes and one of Rome's most beautiful hidden cloisters.

The giant skeleton sculpture is surprisingly well-traveled.

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

Pompeii's less famous neighbor is still revealing her secrets.

This amazingly well-preserved villa just outside Pompeii boasts rare examples of ancient Roman paintings.

This park on the outskirts of Rome boasts two ancient Roman aqueducts and a medieval tower.

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

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

This beautiful park on the outskirts of Rome protects the ruins of two colossal ancient aqueducts.

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

One of seven Jewish catacombs in Rome and one of only two open to the public.

An encyclopedic collection of mammal penises.

This German bone house contains the remains of some 20,000 souls.

In a small churchyard in Dingolfing, Germany the quaint Schusterkapelle is there to remind you of your imminent mortality.

In 1830, cemetery workers in Cham unearthed a chamber housing thousands of skeletal remains from the 13th century, which can still be viewed today.

An Austrian house of bones filled with hundreds of intricately painted skulls.

A church of bones, decorated with 40,000 human skeletons.

A New England curiosity cabinet, one hundred years on.