Syria's ancient cultural heritage is disappearing: Tel Ajaja and its irreplaceable Assyrian artifacts are the latest victims of the more than five-year civil war. The full extent of the damage done during ISIS' two-year control of the area is now clear, say archaeologists: some 40 percent of the 4000-year-old city known to history as Shadikanni was destroyed, the Gulf News reported. The terrorist movement even systemically uncovered areas not yet excavated, finding irreplaceable artifacts that they either destroyed, or may have "saved" for sale on the black market, Syrian archaeologists told the website. Tel Ajaja, located in the north-eastern province Hasakeh, was one of the main cities of the Assyrian Empire, which flourished in the first millennium BCE. Other casualties of war All of human history has passed through the Levant. Yet not all of the damage to the region's heritage has been wreaked by the Islamic State. Much of the birthplace of modern civilization and its archaeological clues lie in regions wracked by war. Syria, one of the world's richest archaeological areas, has been in the front line since civil war erupted in 2011. Ancient ruins of cities and fortresses from Assyrian, Greek, Roman and Byzantine eras are used as cannon mounts and weapon depots.