The most metal church of all time was built in record time because of an international, pious pissing contest.

Climb a steep hill in 90 seconds on the second-oldest urban subway in the world.

Flames have been burning within this mountain for more than 2,500 years.

This crucial gathering spot along the "hippie trail" still displays old notes between traveling beatniks and backpackers.

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

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

This remarkably well-preserved Egyptian plinth is pretty well traveled for a giant piece of stone.

A gorgeous, Gaudí-esque stairway constructed in the city of Istanbul by a prominent Jewish family.

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

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

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

These tombs were built into the side of a mountain so that ancient angels could reach the dead.

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

A marvel of Byzantine engineering under the streets of Istanbul.

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

The building's fluid, wavelike walls are a true feat of architectural ingenuity.

A unique museum dedicated to culture and artistry of carpet weaving.

A fountain filled with golden statues, celebrating the the ancient kingdom of Colchis.

A lively circle of dancers in the Georgian capital commemorates an ancient rite of spring.

Tower with a double-helix spiral, adorned with letters of the Georgian alphabet.

A gleaming white and undulating tower marks the border between Georgia and Turkey.

With over 10,000 lights, this engineering marvel lights up the city after dark.

At this rare mosque in Tbilisi, Sunni and Shia Muslims pray side by side.

This extraordinary, multi-pillared monument depicts the fascinating history of Georgia.