Click Photo for Larger Version
View looking north. This is the covered underground area, just north of the outdoor Men's Prayer area . The arch (half visible) towards the rear of the photo is "Wilson's Arch." It is named after a nineteenth century explorer of Jerusalem.
The date of the arch is disputed: some believe that the present arch is from the Arab period known as the Umayyad Period (ca. A.D. 651-750), but others, including this author, believe it is from prior to A.D. 70 (possibly Herodian). In any case, all believe that the site of this current arch was the beginning of a series of arches that preceded westward, from the Temple Mount, across the Central Valley, to the western hill of Jerusalem. Indeed a series of subsequent arches have been exposed in recent years.
Just beyond Wilson's arch is the (closed) entrance to the Rabbinic Tunnel which proceeds northward along the face of the western supporting wall.