All of the stones visible in this photo were put in place by the workmen of Herod the Great (37-4 B.C.). This wall is part of the western retaining wall of the temple platform on top of which Herod refurbished the actual Temple building.
The plaza in front of the wall was cleared in 1967 and then paved. The Herodian stones descend another 19 courses, for 65 feet [20 m] , below the current plaza level. For centuries, Jews have come here to pray.