Strong fortified walls from fifteen to twenty-five feet thick and twenty feet high surrounded ancient cities. Built into these walls were towers at each corner and at other places in the wall where an enemy might attack. Each tower had its own entrance, a staircase to the top, and a stash of weapons. Towers were the place to run to when the enemy was attacking. These towers were called migdal-oz in Hebrew. The same word is also translated as “stronghold.”