Historian Dan Snow writes that Syria's heritage is under attack - but when the war ends it will be the foundation on which a shredded national identity can be rebuilt.
In August 2012 fire tore through the heart of the Syrian city of Aleppo. One Western journalist said parts of it, including much of the medieval covered market, or souk, were "burned to smithereens".
Old Aleppo is a Unesco World Heritage site, recognised by the world as being internationally significant, a vital piece of humanity's shared past. Central Aleppo was a stunningly preserved medieval settlement, probably the finest example of its kind in the world.
It was as if parts of Stonehenge or the heart of Edinburgh had been wiped out. The fire was caused by the vicious fighting that has swept across Syria since a civil war started in 2011.
More than 50,000 people have been killed, thousands more injured, imprisoned and tortured, and millions made homeless or turned into refugees.