As the ancient remains closest in proximity to the last temple, the Western Wall in Jerusalem is the most important holy site for Jews. It’s the western retaining wall to the Temple Mount, upon which the Temple once stood. The temple itself was destroyed by the Romans in 70 CE.
The Western Wall is generally known as the 200-foot long expanse presiding over the open-air Prayer Plaza. But another 1050 feet of wall extends to the north of the plaza beneath streets and buildings in the Muslim Quarter. Excavation of the area began in the mid-19th century but was limited by Ottoman rulers. Excavation started up again in earnest after Israel took control of the Old City in 1967 and continues still today.
Tunnel tours explore the buried section of the Wall, as well as original steps that lead from the city level up to the Temple Mount, Roman streets, 2nd-Temple era dwellings and ancient cisterns. A section of wall within the tunnels known as Opposite Foundation Stone is especially sacred. It is traditionally held to be the point closest to the heart of the Temple, the Holy of Holies.
In this illustration of the Temple Mount before the Temple was destroyed, the modern prayer plaza lies between the two arches and the tunnel follows the buried section of the wall to the north of the far arch.
Tunnel tours begin on the north side of the Western Wall Plaza and end near the 1st Station of the Cross on the Via Dolorosa.