The only Roman honorific column in Istanbul.

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.

You'll find just about anything in this funky Tbilisi flea market.

The charmingly disheveled clock tower of Tbilisi's puppet theater.

This little medieval church hidden in the center of Yerevan was lost and rediscovered—twice.

The surviving pieces of an ancient aqueduct that may have fed into the lost Hanging Gardens of Babylon.

The sacred shrine of the Yazidis.

9th century Abbasid mosque, damaged in modern warfare.

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

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

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

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

One of the two original gateways into the Kasbah, this gateway is a nesting site for storks.

The designated Jewish quarter in Fez dates back to the 15th century.

This vast masterpiece of Moroccan architecture spreads across 20 acres.

The oldest monument in Marrakesh and the city's only surviving example of Almoravid architecture.

Deliberately hidden for centuries, the magnificent Saadian Tombs were eventually uncovered in 1917.

The largest madrasa in Morocco once housed more than 900 students within its exquisite walls.

The oldest known university in the world is in Fez, Morocco.

Traditional 11th-century outdoor tannery.

Fortune tellers, snake charmers, poets, and storytellers all gather on this historic square in Morocco.

Thousands of narrow alleyways in an ancient medieval city make up what's believed to be the world's largest car-free urban zone.

Mosaics, storks, and brothels—this ancient city has it all.