Tel Megiddo: the water tunnel

This photograph shows an underground tunnel that was part of Megiddo's water system, which was built in the 9th century BCE. Water was a precious defensive commodity - if a city had any hope of surviving a siege, they had to make sure that their inhabitants had water to drink and that their enemies did not. In order to reach the spring that fed the city from within the city walls, ancient engineers cut a 75-foot shaft equipped with a spiral staircase and then a 210-foot long horizontal underground tunnel.