The talk will focus on megalithic phenomena of the southern Levant between the 4th-3rd millennia BC, mostly concentrated along the Jordan Valley rift. I will discuss dolmens, menhirs, tumuli and above all, the mysterious and unique site of Rujm el-Hiri, the most impressive monument in the southern Levant. The talk will survey, besides the chronology and architecture of the monuments, some theoretical issues related to their phenomenology, their meaning and their possible relation to the emerging urbanization of the southern Levant.{[