A narrow passage next to a cafe leads to a courtyard exploding with murals, tags, and paste-ups.

A museum dedicated to the history of a terrifying secret police is now held in their former headquarters.

The largest free-standing aquarium in the world resides in a hotel lobby in Berlin.

The most visited, and possibly most controversial, museum in Germany.

Started as a kitchen garden, now the second largest botanical garden in the world.

A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.

An eerie, derelict amusement park in Berlin.

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

An 18th century fountain and two columns are all that remains of Rome's forgotten river harbor.

This one-of-a-kind Roman arch is not actually dedicated to the god Janus.

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

In Rome’s Jewish ghetto, a 200-year-old bakery still makes the neighborhood’s historic sweets.

Romans decided this 16th-century "talking statue" was so ugly, they named it after a primate.

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

A detailed pachyderm supports Rome's smallest Egyptian obelisk.

A massive marble foot is tucked away in a small alley near the Pantheon.

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

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

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

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

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

The engineering wonder and pleasure dome of a much-maligned emperor still holds undiscovered secrets.

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

An alchemist's "magic door" stands in the middle of a Roman park.