The northernmost 79 meters of this wall are not in the same line as the rest of the wall, but projects around 2.5 meters outwards. Although you can say that was because of a tower that was there, this does not seem to be the case, being that this projection is 79 meters wide, way too wide for a tower.
Right before this projection, the street that runs along the wall stops. The street seems to never have been finished, as there is still a big piece of bedrock that was never cut down. The area to the north of the street was a quarry, from which some of the stones for the Har Habayis were cut. You can still see some of the grooves that were cut to remove the stones.
Also right here, at the northern end of the street, there is two Doric pillars on its west side. These are probably part of a portico surrounding a commercial plaza (called by the Greeks, an agora, and by the Romans, a forum).
To the south of this, there is a large pre-Herodian cistern, which was cut when Har Habayis was expanded. It is roundish, with a diameter of approximately ten meters. There was a staircase to go down into it, starting from the original ground level (before it was cut down for the street). This staircase is still there to this day. The street was built over most of the cistern, and only part of it was left open, with a stone guardrail, rounded on top, built around it. (This cistern is number 46 in Gibson and Jacobson's book about the temple mount cisterns.)
Bahat, Dan. “Jerusalem Down Under: Tunneling Along Herod’s Temple Mount Wall,” Biblical Archaeology Review 21.6 (1995): 30–35, 37–40, 42–47.
Gibson, Shimon and David Jacobson (1996), Below the Temple Mount in Jerusalem: A Sourcebook on the Cisterns, Subterranean Chambers and Conduits of the Haram Al-Sharif
I have added a new video of the Lishkos on the northern side of the first Beis Hamikdash..
My name is Mendel Lewis.
Hashem said to Yechezkel, "Its reading in the Torah is as great as its building. Go and say it to them, and they will occupy themselves to read the form of it in the Torah. And in reward for its reading, that they occupy themselves to read about it, I count it for them as if they were occupied with the building of it. (Tanchuma tzav 14)