While the U.S. and Soviet Union were engaged in a space race, Poland built a UFO on the ground.

Berlin's old airport.

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

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.

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

In the midst of a living monument to Soviet social engineering, Polish Catholics built this church by hand.

A Soviet era flat that refused to conform to the dull gray standards.

This sprawling concrete suburb of Kraków was designed by the Soviet Union as the model proletarian city.

St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

This street has over a half-dozen names, all at once.

A peculiarly shaped brass sculpture hidden in a courtyard in central Lviv

This unique Lady Liberty is one of the only examples of the figure sitting down.

The unsettling remnants of a torn down movie set lies nearby the ruined location of the actual Płaszów Labor Camp.

At first glance, this area seems like just another city park, but the lush landscape hides a dark past.

One of the largest amphitheaters in Europe is a former Nazi German gathering place that still stands today.

The ruins of an ancient Zoroastrian Tower of Silence believed to be the earliest example of the traditional funerary practice.

These "50 Fortresses" have been unearthed in the ancient oasis of Khwarezm.

Ancient barriers wrap around what was once an important stop along the Silk Road.

Once a bustling fishing port, this semi-ghost town is now more than 90 miles away from the shore.

Controversially restored in the 1970s, this giant 15th-century mosque is shrouded in legend.

The Avenue of Mausolea is a series of grand palatial tombs.

Light still pours into the ruins of this ancient Islamic observatory.

More than 10,000 small mirrors cover the curved surface of the world's second-largest solar oven, located in a remote village in Uzbekistan.

This "tower of death" has acted as an observatory, a religious hub, and an executioner's lair.