SYRIA: Analysis of aerial and satellite imagery has revealed the presence of an extensive 4,000-yearold defensive network in northern Syria. This Middle Bronze Age system is composed of as many as 1,000 stone towers, forts, and enclosures, which were erected along the mountainous ridges east of Hama to protect and surveil the landscape. The structures were all built within sight of one another so that communication could be maintained using either light or smoke signals.