Some excavations were conducted just to the West of the Western Wall Plaza in Jerusalem. The excavation area was in the Tyropoeon, close to the boundary of the city. The results are available here for a limited time only. After some use of the area as a quarry, a 7th C BC four-room house was found, with seals and 10 lmlk handles (1 Hebron, 2 Socoh), and eleven concentric circle handles. It was then destroyed by the Chaldeans without fire. No further remains were found until the Herodian era, when a cistern, the remains of the aqueduct, and a plastered installation, probably a mikveh, were found. After that, the remains of the Eastern Cardo, shown by coins and pottery to have been built in Hadrian’s day, not Eudocia’s, and possibly even before Hadrian’s 130 AD visit. This cardo was aligned with that of the Herodian Temple Mount.
The above image shows the excavation area. The results indicated that during the Hasmonean days, and likely during the Late Iron II, the First Wall did not include the excavation area. Looking at the plan of the Temple Mount, it seems likely the First Wall began on the north side of Wilson’s arch.
Update (August 20, 2012)-It looks like I was wrong about my hunch about the First Wall. It seems that a section of the Hasmonean city wall was converted into Wilson’s Arch.