Western Wall Tunnel, pedestrian tunnel in the Muslim Quarter, Old City of Jerusalem, Israel

The Western Wall Tunnel is an underground passage beneath Old City Jerusalem that exposes ancient masonry and subsurface structures from antiquity. It connects different sections and allows visitors to walk through the buried layers that lie beneath this historic city.

The foundation was laid roughly 2,000 years ago when massive walls were built around a sacred mountain. Archaeological investigation since the 19th century gradually uncovered the tunnel system and opened it to the public.

Warren's Gate, about 46 m into the tunnel, was for centuries a small synagogue called "The Cave", where early Muslim rulers allowed Jews to pray close to the Temple ruins. Rabbi Yehuda Getz later built a synagogue just outside the sealed gate, the nearest point where Jews may pray to the Holy of Holies. The Hasmonean Channel, an 80 m water conduit about 1.2 m wide, was first studied by Charles Wilson in 1864 and opened to visitors in 1996.

Access is only available through guided tours that last several hours and must be booked in advance. Wear comfortable shoes since the underground path is uneven and sometimes low, requiring you to duck through certain sections.

Inside the tunnel lies the Western Stone, 13.6 m long and 3 m high; its hidden width was first estimated at 3.5–4.5 m and a weight of 570 short tons, though ground-penetrating radar suggests 250–300 tonnes. The Western Wall Heritage Foundation now gives only "several hundred tons". It is compared to the larger blocks at the Temple of Jupiter in Baalbek.