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

This ancient market is often referred to as the oldest shopping mall in the world.

This subterranean shrine beneath a bike rental store celebrates the iconic Italian scooter.

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

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

This hidden Art Nouveau courtyard is an opulent feast for the eyes.

Architectural monsters are devouring this palace's every door and window.

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

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

An ancient Egyptian obelisk is now used to commemorate fallen Italian soldiers.

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

Ancient ruins hidden underneath a modern luxury hotel.

Where Venice's gondolas go for a tune-up.

The pile of books behind the dignified writer gave the statue a most undignified nickname.

This deconsecrated church has seen many uses, from a tobacco storehouse to a cinema.

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

This palatial spiral staircase was so unusual the name "snail" was given to the noble family who built it.

According to tradition this is the oldest church in Venice, but its actual age is a mystery.

In the past, Renaissance sex workers were encouraged to entice customers on this bridge.

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

Hanging within this medieval church are the bones of a beast allegedly slain by a fourth-century saint.

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

This Venice bookstore has resigned itself to constant flooding by keeping its books in bathtubs and boats.

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.