Large towers were usually built into the walls of Troy to defend a major gateway. The South tower was built to guard the Scaean Gate.
The Eastern wall was also reinforced by a large tower. This
massive bastion at the north east corner of the city was built to defend a well
which was the main water supply.
The total width of all the Troy wall sets together, as
seen in the above picture will be 32" and approximately 8" depth.