Mysterious lost empire of the Silk Road.

The Syrian headquarters of alleged hashish-smoking assassins.

One of the oldest and largest castles in the world.

Amid the rubble of Aleppo's Old Quarter, part of a historic market has been restored and re-opened.

Three members of Syria's ruling family entombed in quiet mountain town.

Ruins of the Crusaders' headquarters.

Only a handful of these gorgeous historic waterwheels remain but even those are in danger from local unrest.

This ancient mountain monastery welcomes all manner of faith in an effort to keep Christians in Syria.

This ornate mosque is said to hold the remains of Muhammad's granddaughter beneath its dome of pure gold.

3D war panorama in Damascus built with help from North Korea.

One of the oldest monasteries in the world is a key pilgrimage site for both Muslims and Christians.

A patchwork of ruins from various civilizations in one of the world's oldest continually inhabited cities.

These towering cliffs jut dramatically from the middle of a barren desert.

The burial ground of two kings and a queen is now a calm city park in the middle of bustling Seoul.

A museum dedicated to the former country.

A pair of connected skyscrapers form this symbolic gateway.

In the hinterlands of Serbia's capital, a giant reflective mushroom houses an aeronautical history of the former Yugoslav republic.

Destroyed Serbian army headquarters sits half crumbled in a largely revitalized Belgrade.

A towering spire in the fortress of Kalemegdan honors the victorious armies of Serbia during their struggles against the Ottoman Empire.

A Serbian church lit by chandeliers made of weapons.

A misnamed well, with a deep dark past.

The unusual sculptures are believed to be powerful political symbols.

The most alien-looking place on Earth.

A giant bisected onion dome remembers the Iraqis who died in the Iran-Iraq War.