In anticipation of a siege by the Assyrian king Sennacherib, Judean king Hezekiah constructed a tunnel to bring water into Jerusalem from the Gihon Spring.
The Siloam Tunnel Inscription is an ancient graffiti in Hezekiah's Tunnel. Its translation is below.
"[...when] (the tunnel) was driven through. And this was the way in which it was cut through: While [...] (were) still [...] axe(s), each man toward his fellow, and while there were still three cubits to be cut through, [there was heard] the voice of a man calling to his fellows, for there was an overlap in the rock on the right [and on the left]. And when the tunnel was driven through, the quarrymen hewed (the rock), each man toward his fellow, axe against axe; and the water flowed from the spring toward the reservoir for 1200 cubits, and the height of the rock above the head(s) of the quarrymen was 100 cubits." Shanks>
Shanks, Hershel. 2008. Sound Proof: How Hezekiah’s Tunnelers Met. Biblical Archaeology Rreview 34:05, Sep/Oct 2008. link