IBeginning in 1967 a tunnel was excavated along the entire length of the Western Wall of the Temple Mount, passing beneath the buildings of the Muslim Quarter of the Old City of Jerusalem. The initiative for this excavation was taken by the Israel Ministry of Religious Affairs, which sought to become familiar with the Western Wall and the reasons for it having become a focus for Jewish prayer.Remains of several periods of construction have been found in the tunnel. At the northern end a massive pre-Herodian water channel was discovered. The monumental Herodian period construction characterized by huge ashlars was found the entire length of the tunnel. It became clear that Herod did not complete the construction project at the northern end of the Western Wall. One of the four western gates of the Temple Mount, known today as Warren’s Gate after its discoverer, is now visible to visitors. It is of great significance as, according to historical sources, its proximity to the Holy of Holies of the Temple made this a place of Jewish prayer in the medieval period. As this area became inaccessible following the construction of Mamluk buildings here in the 14th–15th centuries, the portion of the Western Wall at today’s Prayer Plaza replaced it.The 70 CE destruction wrought by the Romans to the walls of the Temple Mount enclosure is evident in the Tunnel and includes a pile of collapsed building stones. Following their foundation of the pagan city of Aelia Capitolina, the Romans constructed a large bathhouse in the area of the southern part of the Tunnel. There is also evidence of Jerusalem’s subsequent history: Byzantine period dwellings; a bridge connecting the Upper City with the Temple Mount in the Early Islamic period that replicates a similar Second Temple period bridge whose remains were also found in the Tunnel; remains of a Crusader period church. This was followed by Mamluk period urbanization covering the area abutting the Temple Mount’s western wall with public buildings, blocking most of it from sight until an earthquake in 1546 exposed the small portion that would become a Jewish place of prayer.The discoveries at the Western Wall Tunnel enrich our knowledge of Jerusalem’s history. This book describes the rich finds uncovered through decades of research.