This basilica is dedicated to two saints, one of which is known more for his famous quote.

This large, circular tomb is the final resting place of the first emperor of Rome.

A hidden three-foot-wide house separates these two regal churches.

A surreal pile of colorful junk fills a small yard in an otherwise gray neighborhood.

This memorial complex contains several mass graves for victims of the Siege of Leningrad.

One of downtown Berlin's last reminders of its Communist past.

At one of Berlin’s oldest churches, visitors can place mosaic tiles to help restore a medieval mural.

The last remnants of a massive medieval wall that once encompassed the city of Berlin.

This dazzling Buddhist temple was constructed from over one million ceramic tiles salvaged from a British shipwreck.

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

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

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

This statue is the only female representation of Rome's "talking statues."

Also known as the Square Colosseum, this building is a prime example of fascist-era rationalist architecture.

A detailed pachyderm supports Rome's smallest Egyptian obelisk.

Gods clash with machines in a power plant regenerated as a museum.

This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

The skull of the patron saint of lovers lies in the Basilica di Santa Maria in Cosmedin—maybe.

Rome's semi-secret peephole vista is also a former Crusader stronghold.

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

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

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

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

A mysterious shape catches the eye in this 16th-century painting.