This small chapel is built of human bones and decorated with a golden skeleton.

The world's oldest bookshop still in operation.

A 16th century chapel decorated with bones, skulls, and entire bodies hanging from the wall.

One of the most beautiful bookstores in the world hides a neo-Gothic interior behind an art nouveau facade.

A small museum displays some of the artifacts discovered during a subway station renovation.

The remains of this misplaced church were moved here stone by stone.

This hydrochronometer was invented by a Dominican monk and is a prime feature in this garden.

This is the oldest Roman-made bridge in the city still existing in its original state.

This curious, round temple is the oldest still-standing marble building in Rome.

Stone memorial that's said to predict the death of the pope and the site of the Cadaver Synod.

This ancient trail climbs the mountain where a Latin League cult worshipped Jupiter, its main deity.

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

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

A magnificent waterfall is also home to the remains of a Roman hydraulic engineering system.

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

A treasure trove of Renaissance-era funerary art in a Roman church built on top of Nero's grave.

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

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

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

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

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

The Pope’s secret escape route.

A Nesting Doll of Churches.

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