Why Two Gates?
The southern wall was the only side of the Har HaBayit (Temple Mount) that had two gates (entrances) as all of the other sides had only one gate each. (Kiponos on the West, Taddi on the North, and the eastern gate upon which was engraved the city of Shushan.)
The reason there were two gates on the southern side is because that’s the side of the Har HaBayit (Temple Mount) that saw the most foot traffic since the city of Jerusalem (of that era) was built to the south of the Temple Mount. The inhabitants naturally used the southern gate to enter and exit. This is also why the southern side of the Har HaBayit had the largest amount of open space before the walls of the Azarah (Courtyard of the Beit HaMikdash).
The eastern side had the next largest amount of space as the people (from the southern side) would turn right in order to enter the Azarah from the eastern side.
