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

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

A mysterious ancient cemetery with Roman sarcophagi and Lycian inscriptions.

Hidden just under the waters around this Turkish island are the ruins of a once great city.

Roman ruins, natural methane fires and a lovely beach.

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

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.

Mausoleum and Holy Seat of Antiochus I of Commagene.

Built entirely of interlocking pieces, construction of this Chinese Muslim house of worship required zero nails.

Hundreds of caves filled with thousands of centuries-old statues and murals.

The western-most fortress on the Great Wall of China has gone from a strategic stronghold to a kitschy tourist carnival.

These layered sandstone mountains in China look like they are made of pressed crayons.

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

Colorful mineral deposits turn these mountains into an Impressionist fantasy.

The largest covered bazaar in the world.

Modern-day cave dwellers carve elaborate homes out of volcanic debris.

The tower in this 1,000-year-old mud-brick village seems to vibrate for no apparent reason.

This remote mountain shrine is one of the most sacred Zoroastrian temples remaining in the world.

17th century mosque for Shah Abbas' harem.

This 17th-century structure is a beautiful testimony to traditional Persian architecture

Marked by the hand of the explorer Henry Morton Stanley.

The ancient necropolis houses the immense rock-cut tombs of four Persian kings.

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