A spectacular rainbow of stained glass makes the "Pink Mosque" one of the most beautiful in Iran.

The palace of the King of Kings, burned by Alexander the Great.

Buddhist pilgrims journey to this sacred rock to leave offerings and have their wishes granted.

Enormous statue of the Emperor of the Mongols.

A stunning 18th-century site where pilgrims ascend by a series of punishing stairs only to return via funicular.

This Dresden church was purposely rebuilt Protestant after being demolished in World War II.

This symbol of Polish heritage survived the occupation during World War II, hidden in plain sight.

A cluster of headless, armless sculptures looms within a popular Polish park.

Once a giant gingerbread factory, this space now hosts exhibits and workshops on the historic treat.

This uber-quaint Polish village is known for its habit of painting elaborate floral motifs on just about everything.

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

Real bones which are said to have belonged to a Polish dragon.

A sacred lake with thousands of sacred carp and a biblical history.

Standing proud atop a Turkish bluff, this Ottoman palace has retained its grandeur despite being abandoned for centuries.

A Turkish monastery tucked into a cliff wall.

The deepest underground city in Turkey was designed to protect 20,000 people behind massive stone doors.

While not Turkey's deepest underground city, this subterranean redoubt is the largest.

In this historic region, homes and churches are carved into ancient volcanic rock formations.

Amid the rubble of Aleppo's Old Quarter, part of a historic market has been restored and re-opened.

One of the oldest and largest castles in the world.

Only a handful of these gorgeous historic waterwheels remain but even those are in danger from local unrest.

A 1,500-year-old ghost settlement is slowly fading away.

Mysterious lost empire of the Silk Road.

Ruins of the Crusaders' headquarters.