The southeastern corner tower

   In the southeastern corner of the expanded Har Habayis, there was a tower, the remains of which can be seen in the eastern wall. This made a nice visual balance to the eastern wall of the Har Habayis, as it had towers on both ends. 

  At 20.3 meters (66 ft 7 in) away from the southern corner of the eastern wall, a vertical line, or offset, can be seen in the wall, starting five stone courses below the floor of Shlomo's stables. This line is created from the stones on the south side of it projecting slightly from the wall. As the wall gets higher, and each stone course of it is set back more, the projection deepens. This is not a separate building than the rest of the wall, as is shown from the fact that the projection is sometimes cut out of the same stone, with the northern part of the stone being cut so it doesn't project as much as the southern side. Based on remains inside Shlomo's stables, Shaul Schaffer estimates that the tower extended 17 meters (56 feet) to the west.

    By this corner of the Har Habayis, remains of a blocked-up window, two stone courses high, can be seen in the southern wall, and three windows, each one three courses high, can be seen in the eastern wall. the lintels of the eastern windows are actually the springers of a vault, showing that the chambers in the tower had a vaulted roof. 

The window in the south wall (Davidbena, CC BY-SA 4.0 via Wikimedia Commons)

Warren's drawing of the southern end of the east wall

reference

​Conder, Claude Reignier, and Warren, Charles. The Survey of Western Palestine: Jerusalem. London, 1884

​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​.
​
​Ritmeyer, Leen. The Quest: Revealing the Temple Mount in Jerusalem. Israel: Carta, 2006.

הר הבית נזר תפארתנו, מאת שאול שפר, ירושלים תשכ"ט