As the Syrian crisis enters its third year, an end to the violence in the country is nowhere to be seen. The world has become accustomed to rising death tolls and reports of shelling and destruction. However, another threat looms in Syria, and this time it is targeting its cultural heritage.

Palmyra, one of the oldest cities in the country, has been subjected to intermittent shelling by forces loyal to President Bashar al-Assad.

The ruins of the city, which is one of UNESCO’s World Heritage sites, date back thousands of years. “Bombs and rockets come in all directions,” eyewitnesses said.

Assad forces have struck the Roman Temple of Bel – built in 43 A.C. – and damaged its northern wall, eyewitnesses said, adding portions and stones of the wall have been destroyed....