Part of a massive 3,700-year-old defensive wall has been uncovered in Jerusalem on the slopes of the Kidron Valley below the City of David. Experts believe it is part of a passage that led to a spring protected by fortifications. The spring, the Gihon, is still in use today.

Excavation director Ronny Reich speculates that there may be further architectural ruins behind the wall. It is believed that ancient Canaanites built the enormous boulder wall, but excavators are at a loss to know how they completed the project and created such straight-sided fortifications (Kevin Flower, "'Massive' Ancient Wall Uncovered in Jerusalem," CNN.com, Sept. 7, 2009).