A sixth-century Byzantine cistern hidden below a modern carpet store.

The ancient abodes are a testament to human ingenuity amid harsh climates.

A charming beach town in Turkey captures all the colors of the rainbow.

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

A marvel of Byzantine engineering under the streets of Istanbul.

The ornate miniature mansions were built for Istanbul's feathered residents.

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

An abused and forgotten metropolis, abandoned for centuries.

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.

This ancient subterranean megalopolis is known for the hot oil traps that were installed above each of its entrances.

The best-preserved ancient theater in the world.

The only residents of this abandoned housing development full of identical castles are stray cats and dogs.

This hidden gem is bathed in beautiful natural light.

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

Live a night as a Byzantine King, with a minibar and private jacuzzi.

The secret room where early Bolsheviks cranked out propaganda fliers on a smuggled printing press.