"Due to the armed conflict in Syria, the conditions are no longer present to ensure the conservation and protection of the outstanding universal value of the six World Heritage properties," the United Nations Educational, Scientific, and Cultural Organisation (UNESCO) noted.

The World Heritage Committee, which was responsible for the determination of which sites will make it to UNESCO's World Heritage Sites list, decided to take action to preserve Syria's threatened cultural heritage.

The Ancient City of Aleppo, Ancient City of Bosra, Ancient City of Damascus, Ancient Villages of northern Syria, Crac des Chevaliers, Qal'at Salah El-Din and the Site of Palmyra are now considered endangered.

The Syrian violent conflict involving the forces loyal to President Bashar Al-Assad and the opposition poses potential risks to the properties that are "recognised by the international community as being of outstanding universal value for humanity as a whole."

The ancient city of Aleppo is the site of the famous Umayyad mosque. The minaret of the structure is just one of the casualties of the violence that started in March 2011. It was destroyed in April of this year.

Last year, the same city's souk or market was damaged by fire which was triggered by gunfire and shelling during one of the violent battles.

The Ancient City of Bosra is home to a 2nd century Roman theatre, several mosques and early Christian ruins.

The Ancient City of Damascus was one of the oldest cities in the Middle East, dates as far back as the 3rd millennium B.C. It is also where the 8th century Great Mosque of the Umayyads which rests on the soil of an Assyrian sanctuary may be found. Otherwise known as the Great Mosque of Damascus, the structure is regarded as the fourth holiest place in Islam by some of its believers.

The Ancient Villages of Northern Syria or the Dead Cities or Forgotten Cities consist of abandoned settlements situated between Aleppo and Idlib. Giving a glimpse of rural life from as far back as the 1st century is its well preserved architecture.

The Crac des Chevaliers and the Qal'at Salah El-Din or Fortress of Saladin are castles which represent that evolution of fortified architecture in the Near East during the 11th - 13th centuries. Fortifications, in architectural terms refer to structures which are built for defence in warfare.

The Site of Palmyra is where the ruins of what were once the most important cultural centres of the ancient world are located.

United Nations Architecture