>> three years of civil war has smashed many of syria's landmarks to dust. these are pictures before the war, showing just some of the 290 cultural heritage sights that have since been damaged. and this is what it looks like now. the united nations is calling for an international effort to protect remaining structures. >> basically this amounts to raising from our collective human kind memory entire portions of our cultural history. >> both sides in the conflict have used ancient fortresses for military bases. syria's armies in the citadel, one of the world's oldest castles. and force jofrs ran that crus e crusader fortress. the army retook it after months of bombardment.