Deep below the surface of biblical Jerusalem lies a series of ancient waterways and chambers. Who built them and why? Recent discoveries of huge ashlars, now underground, have revealed surprising evidence about how its earliest inhabitants safeguarded their city’s most important water source, how King David’s men may have conquered the city, and how King Hezekiah was able to withstand the siege of the powerful Assyrian army. Join with us as we explore the underground mysteries of one of Jerusalem’s most fascinating tales.