Courtesy Arad Expeditions

Two Arads: On the right (west), the excavated Canaanite city (3200–2050 B.C.) sprawls across 25 acres in Israel’s Negev Desert. Its enclosure wall with three towers budding outward around the curve may be seen clearly. Atop the nearby hill, left, the Israelite citadel (1200–586 B.C.) emerges from the sand.

Between the two sites, in a depression in the hill (arrow), excavators discovered remains of the water-collecting systems the ancients had devised: a reservoir used by the Canaanites and a well dug later in the same location by the Israelites (see photos).