Todd Bolen/

Hezekiah’a Tunnel weaves its way underneath the City of David, connecting the Gihon Spring in the east to the Pool of Siloam in the southwestern end of the city. The 1,750-foot-long water tunnel was dug by two teams of workers, who started at different ends of the tunnel and eventually met in the middle. While the date and purpose of the Siloam Tunnel—or Hezekiah’s Tunnel—is often debated, it is typically attributed to King Hezekiah in the eighth century B.C.E. with the purpose of preparing Jerusalem against the impending siege of the Assyrian king Sennacherib.