A group of artists transformed this desolate city alleyway into an outdoor gallery of street art.

Just like in Hollywood, Madrid has also a forgotten walk of fame.

These narrow stone granaries have been used to store and dry out grain for hundreds of years.

The only remaining arch of the oldest stone bridge in Rome stands in the middle of the Tiber.

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

The remains of this 2nd-century Roman temple are incorporated into a modern building.

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

These hut foundations are believed to be the residence of Romulus, founder of Rome.

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

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

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

One of Catholicism's four major basilicas has a series of papal portraits that are said to predict the end of the world.

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

A detailed pachyderm supports Rome's smallest Egyptian obelisk.

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

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

One of the most powerful religious centers in the Middle Ages, dubbed the founder of Western monasticism.

For decades, Puerta del Sol has been illuminated by a giant, guitar-wielding bottle of sherry.

This macabre masterpiece of a mural is one of Francisco Goya's "Black Paintings."

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

Breathtaking and huge 430 year old maps of Italy.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

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

The best preserved Paleochristian basilica in Rome hides a number of oddities and secrets.