A hidden network of subterranean passageways lies tangled beneath Indianapolis' bustling City Market.

A medical facility that has been kept frozen in time.

A burial vault located under Tiber Island in the middle of the Italian capital.

In Rome’s Jewish ghetto, a 200-year-old bakery still makes the neighborhood’s historic sweets.

A hidden workshop for creating and restoring Papal mosaic masterpieces.

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

Jesus' footprints and the first catacombs in the world.

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

Naturally preserved bodies are eerily staged throughout the crypt in varying poses.

The venerated body of a 12th century saint is celebrated each year with the 'Race of the Candles.'

This 21st century cabinet of curiosities includes dinosaur bones, moon rocks, film memorabilia, and more.

This museum is rotten with a century of wax medical deformities.

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

Thousands of well-dressed mummies below a monastery.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

These "anatomical machines" are only one of the many strange items in this Italian crypt.

Skulls from the plague of 1656 and World War II bombings are united by a cult dedicated to caring for the ancient dead.

A submerged archeological park still holds the wonders of a Roman Sodom.

The largest and most famous wax anatomical collection anywhere in the world.

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

The middle finger of modernity.

A dismembered holy head stares out from her beautiful reliquary at the St. Dominic Basilica.

2300-year-old Roman road connecting the empire.

The final resting place of the poets Shelley and Keats.