A huge enchanting public park just outside the ancient walls of Rome.

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

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

This large, circular tomb is the final resting place of the first emperor of Rome.

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

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

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

Inside this McDonald's you can dine on your Big Mac and fries next to a 2,500-year-old Roman wall.

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

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

A forgotten "city of water" underneath the famous Trevi district.

The Pope’s secret escape route.

A Nesting Doll of Churches.

A collection of objects supposedly singed by the hands of souls in purgatory.

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

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

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

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

A fairy tale castle in modern Rome.

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.

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

The final resting place of the poets Shelley and Keats.

Along with used instruments, this pawn shop has pieces of music history on display.