"Holy Wisdom" overlooks the city that became its namesake.

A gigantic statue of a Russian soldier watches over the ancient city of Plovdiv, a prominent reminder of the Soviet period in Bulgaria.

This ancient theater, restored in the 20th century, lives on as a venue for dramatic and musical performances.

This historic black and white monastery is one of Bulgaria's architectural jewels.

A spectacular Bulgarian cave resembling a devil's head with a waterfall rushing down its throat.

An architectural marvel that spans the Arda River, and has stories of a haunted past.

Five sultans and their families rest in eternal splendor, teeming with overlooked beauty and drama.

A marvel of Byzantine engineering under the streets of Istanbul.

This famous city eluded concrete detection until the early 2000's.

Roman ruins top white travertine terraces formed by ancient hot springs.

A Turkish ghost town abandoned in a population exchange with Greece.

A Lycian city of the dead carved into the hillside of Southern Turkey, complete with startlingly human touches.

Roman ruins, natural methane fires and a lovely beach.

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

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

This incredible stone temple is a monument to death, victory, and fantasy architecture.

This ironic war memorial thumbs its nose at a campaign of inedible humanitarian aid food products.

Oriental bazaar in the heart of Sarajevo.

The place where World War I began.

This historic timepiece is thought to be the only public clock in the world that keeps lunar time.

A number of craters left by fatal mortar strikes have been filled with red resin to remember those lost during the Siege of Sarajevo.