Hezekiah's Tunnel, or the Siloam Tunnel is a tunnel that was dug underneath the City of David in Jerusalem before 701 BC during the reign of Hezekiah. The tunnel is mentioned in 2 Kings 20:20 in the Bible.
This article below is from Wikipedia
The Bible also tells us that king Hezekiah prepared Jerusalem to an impending siege by the Assyrians, by "blocking the source of the waters of the upper Gihon, and leading them straight down on the west to the City of David" (II Book of Chronicles chapter 32). The tunnel has been securely dated both by the written inscription found on its wall (Siloam Inscription), and by dating organic matter contained in the original plastering. It is one of the few intact, 8th century BC structures in the world that the public can not only visit, but enter and walk through.
The tunnel, leading from the Gihon Spring to the Pool of Siloam, was designed to act as an aqueduct to provide Jerusalem with water during an impending siege by the Assyrians, led by Sennacherib. The curving tunnel is 533 m long, and by using a 30 cm (0.6%) gradient altitude difference between each end, conveyed water along its length from the spring to the pool. READ MORE http://en.wikipedia.org/wiki/Hezekiah%27s_tunnel
2 Kings 20:20 (New International Version) 20 As for the other events of Hezekiah's reign, all his achievements and how he made the pool and the tunnel by which he brought water into the city, are they not written in the book of the annals of the kings of Judah?
Dear friends if you don't know the Lord Jesus yet, time is running out in this evil world FAST.
God is always listening, and he will be there for you when you choose to speak to him. All I ask is that you don’t wait UNTIL IT IS TO LATE. CLICK HERE and watch this VIDEO and Surrender Your Heart To God. Because He Loves YOU AND WILL SAVE YOUR SOUL.