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

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

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

The ruins of the largest gladiatorial school in Rome are largely hidden under modern streets.

The city of Palestrina was built around this magnificent terraced sanctuary dedicated to the pagan goddess Fortuna.

This small church was constructed over the ruins of three temples dating to the Roman Republic.

Legend has it that this bronze orb, which sat atop an ancient Egyptian obelisk, once held the ashes of Julius Caesar.

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

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

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

The "Great Sewer" of ancient Rome is one of the oldest sewer systems in the world, and is still in use.

This small, ancient Roman temple was once a church dedicated to the patron saint of penitents.

The yawning maw of this pagan visage is said to bite off the hands of liars.

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

Rome’s legendary peephole vista is also a former Crusader stronghold.

The final resting place of the poets Shelley and Keats.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

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

What looks like a normal building is really a hollow facade hiding a subway vent.

This old KLM airplane cut into three parts was transformed into an eclectic airport gift shop.

Europe's official "zero-level," the equator of elevation.

This city square is home to Amsterdam's oldest church and a statue honoring Dutch sex workers.

A Dutch passageway's artistic, aquatic-themed makeover pays tribute to the capital city's famed waterways.

The world’s largest street art museum.