A gorgeous, Gaudí-esque stairway constructed in the city of Istanbul by a prominent Jewish family.

Five sultans and their families rest in eternal splendor, teeming with overlooked beauty and drama.

This remarkably well-preserved Egyptian plinth is pretty well traveled for a giant piece of stone.

A small etching on the white marble parapet was written in runic script by a Viking mercenary.

A marvel of Byzantine engineering under the streets of Istanbul.

This Roman statue is missing a limb from when the Venetians stole it from Constantinople during the Crusades.

Thousand-year-old Viking runes adorn an ancient Greek lion at the entrance to the Venetian Arsenal.

100 year tradition of fist fights, marked by marble footsteps.

Go inside to really appreciate this 500-year-old technological masterpiece.

The first statue to be added to Saint Peter's Square in over 350 years is an ode to migrants and refugees around the world.

Breathtaking and huge 430 year old maps of Italy.

Historic fortifications form the boundary of Vatican City, but it’s not entirely surrounded by walls.

This equestrian statue of Constantine the Great has been the subject of criticism for centuries.

A freedman baker’s lavish tomb has a relief showing various stages of Roman bread making.

Inside this building is another country within Rome, a sovereign entity without a physical territory.

An 18th-century post box used to alert the church of sick and ailing foreign pilgrims.

This unassuming bridge is most likely one of Michelangelo's unfinished masterworks.

Plaques on its facade commemorate the Tiber's most destructive deluges.

A sculpture serving as an homage to Pope John Paul II.

An unremarkable wooden wheel built into the side of one of Rome's oldest hospitals was part of a policy to reduce infant exposure.

Italian horror legend Dario Argento’s own shop hides a sinister museum-dungeon in the basement.

A secret hatch containing two parchments was discovered in this statue over 40 years after its installation.

An ancient Roman temple first dedicated to an emperor's wife is now a church.

A monumental fountain in Rome features a large statue of Moses that has been criticized for centuries.