Tel Arad, northwest of the modern Israeli city of Arad, in the northern Negev, consists of a lower and an upper city. The lower city was inhabited in the Early Bronze Age (3150-2200 BCE). At approximately 100 dunams (25 acres) Arad was one of the largest cities of its day in this country, surrounded by a strong 1,200-meter wall. The city's streets, plazas, and buildings were meticulously planned, including a reservoir in the lowest part of the city to which surface runoff was channeled.