This gallery commissioned by Cardinal Spada is known for its magnificent optical illusion.

Inside this striking glass building, visitors can see thousands of dinosaur fossils in the positions that nature deposited them more than 150 million years ago.

Experience the glam side of air travel without leaving the ground at this speakeasy.

It's believed emperor Hadrian himself funded this once architectural wonder.

England's most famous front door has an accidental doppelganger.

This generously endowed statue once stood guard outside a Roman home.

Catalonia Tradition: Beating the hollow Christmas log until it defecates in your fireplace.

Possibly the oldest church in Barcelona, this basilica has its pagan and Christian mythologies all mixed up.

Gaze upon chocolate sculptures depicting everything from chariot races to Gaudí's famous church at this shrine to sweets.

According to local folklore, this Roman sepulcher was once a throne for the Devil.

This small Roman arch was transformed into a dwelling by the founder of the Trinitarian Order.

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

Roman politician Herodes Atticus built this nymphaeum to honor his wife, whom he may have murdered.

Known for centuries as the famous Roman emperor's burial place, this monument is actually something else.

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

A fortified medieval basilica on the Caelian Hill preserves extraordinary frescoes and one of Rome's most beautiful hidden cloisters.

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

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

The most gigantic, swoony, intimidating trio of fingers in all of antiquity.

A century-old tradition has culminated in a small but singular collection of feline effigies.

These lovely Turkish-styled baths were brought back to life after winning a reality show competition.

One of Europe's oldest libraries.

A Roman spa buried deep beneath the City of London.

During this Shetland Islands celebration, hundreds of torch-carrying "guizers" lead a procession to burn a viking longboat.