About 700 BC, by Hezekiah, as Kings and Chronicles say: the radiometric dates and the script of the inscription agree.
Held by Most scholars; Frumkin, Shimron and Rosenbaum (2003).
For
- Radiocarbon dates of plant remains in the plaster and uranium–thorium dates of stalactites point to about 700 BC.
- Kings and Chronicles credit Hezekiah with bringing the Gihon's water into the city.
Against
- Neither book names this tunnel; Reich and Shukron read the pottery at its northern end as earlier.
Sources: A. Frumkin, A. Shimron and J. Rosenbaum, “Radiometric Dating of the Siloam Tunnel, Jerusalem”, Nature 425 (2003); R. Reich and E. Shukron, “The Date of the Siloam Tunnel Reconsidered”, Tel Aviv 38 (2011)
