Gihon Spring
The Pool of Siloam was built during the reign of Hezekiah (715–687/6 BCE), to leave besieging armies without access to the spring's waters. The pool was fed by the newly constructed Siloam tunnel. An older Canaanite tunnel had been very vulnerable to attackers, so, under threat from the Assyrian king Sennacherib, Hezekiah sealed up the old outlet of the Gihon Spring and built the new underground Siloam tunnel in place of the older tunnel ().