Western Wall Tunnel

The Western Wall Tunnel is a tunnel exposing the Western Wall slightly north from where the traditional, open-air prayer site ends and up to the Wall's northern end. Most of the tunnel is in continuation of the open-air Western Wall and is located under buildings of the Muslim Quarter of the Old City of Jerusalem. While the open-air portion of the Western Wall is approximately 60 metres long, the majority of its original length of 488 metres is hidden underground. The tunnel allows access to the remainder of the Wall in a northerly direction.

The tunnel is connected to several adjacent excavated underground spaces, many of which can be visited together with the main tunnel. For this reason the plural form, Western Wall Tunnels, is often used.

Source: Wikipedia