The Syrian headquarters of alleged hashish-smoking assassins.

Also known as the Great Mosque of Damascus, this is one of the world's largest and oldest mosques.

One of the world's best-preserved Roman amphitheaters is also one of the most unusual; it's made of black volcanic rock.

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

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

One of the oldest and largest castles in the world.

Ruins of the Crusaders' headquarters.

Mysterious lost empire of the Silk Road.

A curious art park at the geographic center of Europe is home to 3,000 television sets and other wonders.

Open-air museum with a large collection of Soviet-era statues.

Over time, this castle grew to encompass the entire island.

A creepy statue of a hooded ghost hauls itself up from the water in a historic Lithuanian city.

Legend has it that Napoleon Bonaparte fell in love with this Gothic church.

An old hill fort covered in over 100,000 crosses is a symbol of Lithuanian nationalism and beliefs.

This stunning, out-of-the-way Croatian monument commemorates a community's uprising against occupying fascist forces.

Construction of this bridge was once described as an "act of violence" against a neighboring country.

The oldest arboretum on the Dalmatian coast doubles as the gardens of Kings Landing in "Game of Thrones."

This huge metal monument is slowly being stripped to its concrete skeleton.

A strangely forgotten claimant to the much contested title of "Source of the Nile."

Fine dining 20 feet below the surface in the Indian Ocean.

This harsh mountain path was built as a strange attempt to improve the health of Turkmen citizens.

A major pre-Columbian archaeological site in central El Salvador.

The stunningly blue waters of these beautiful caves also have a violent past.

The largest prehistoric ruins south of the Sahara, once a powerful center of international trade.