The water system at Megiddo is one of the most impressive in ancient Israel. The first excavators dated it to the Late Bronze period (1400-1200 B.C.E.), but Yigael Yadin, excavating on behalf of the Institute of Archaeology of the Hebrew University, showed that the water system’s earliest use was during the ninth century B.C.E., perhaps by King Ahab. In order to reach the spring water from within the city walls, the ancient engineers cut a 75-foot shaft equipped with a spiral staircase, and then, from the base of the shaft, cut a horizontal tunnel 210 feet long to reach the spring water. This shaft and tunnel system provided a secure water supply to the city during times of siege.