Located in what is now called Ir David, the Old City of Jerusalem was the last bastion of King Hezekiah in a country that had been destroyed all around him by the Assyrians circa 701 BCE. To fortify Jerusalem, King Hezekiah built a protective wall but was then faced with the challenge of bringing water into the city for the residents. There was a spring that ran beyond the wall, but the king wanted to make the water inaccessible to the enemy, yet available to the Jewish residents within the walled city. To accomplish the former, he had workers clog and camouflage the water source. For the latter challenge, his workforce dug a tunnel from the camouflaged water source to a pool inside the walls, thus having the water flow freely into it. To ensure the flow of water, they had to build the reservoir in the deepest part of the city and carve, at an angle, a 533-meter long tunnel underneath the City of David mountain. To hasten the work, two teams of tunnelers dug toward each other from opposite ends of the tunnel. The fact that they succeeded and met at the exact midpoint is regarded as one of the greatest engineering feats of ancient times. Various theories exist as to how this was actually accomplished. One premise is that there was a crack through which water was already seeping, and the workers enlarged it. Such an opening would also have provided oxygen for the tunnelers to breathe. Getting your feet wet To explore this pool on your own, walk through Hezekiah's Tunnel and continue down the steps into the water. The whole experience takes about half an hour of wading through knee-deep spring water. It is recommended to wear plastic sandals and to bring a flashlight. When you emerge from the tunnel, you will find yourself in the Byzantine Pool of Siloam (Shiloah). Climb the steps out of the pool and descend more steps, which will lead you into the Second Temple Shiloah Pool and the Herodian Road. Excerpted from Jerusalem: Footsteps through Time by Ahron Horovitz.