Heralded as the world's first theater, these ruins are often overlooked as they reside in the shadows of the Acropolis.

A minotaur, a labyrinth, and a dubious restoration pull in visitors from around the world.

The Cycladic architecture makes this Athens neighborhood feel like an island paradise hidden in the shadow of the Acropolis.

The railway carts travelers to central Athens's highest peak, which offers stunning vistas of the city.

A 2,000-year-old computer demonstrates remarkable engineering and astronomical precision.

The hallucinogenic center of the ancient world.

This monumental work of art symbolizes the coming together of a previously divided city.

A monument to the three wars that led to German unification towers within a Berlin traffic circle.

Metro station with a claim to rock n' roll fame.

Cold war icon and onetime "hole" in the iron curtain.

These former Nazi anti-aircraft towers offer a singular view of the north of Berlin in the summer, and a sanctuary for bats in winter.

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

An abandoned NSA listening post on Berlin's "Devil's Mountain."

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

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

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

The abandoned "Red Star Train Graveyard" is the final rusting place for precious artifacts of train history.

Hungarian Jews were ghettoized during the Second World War, but little remains of the original wall that closed the Jewish people off from the rest of the city.

The holes in this wall provide a glimpse into Jewish life in Budapest, both past and present.

On Gellért Hill, this statue depicts the tragic tale of lovers divided by the Danube.

A museum dedicated to a secret military hospital hidden beneath a castle in Budapest.

Budapest's Communist-era statues, banished to the suburbs.

Tucked away near more famous landmarks lies a statue meant to symbolize the confluence and continuing development of human culture.

A Trabant car, a kangaroo statue, and a plethora of plants take over this abandoned-factory-turned-bar.