A picture, looking west, at the lower portion of the eastern slope of the City of David that is located just north of the southern tip of the city.
The wall above the rock scarp, more or less in the central horizontal portion of the image, is where the massive 18th century BC wall was constructed—its lower portion resting on the bedrock. This wall was restored in the late 8th century, perhaps by King Hezekiah, to protect the city from the anticipated invasion of the Assyrian, Sennacherib. This 8th-century rebuild is composed of the smaller stones above the 18th-century wall.
Then he [Hezekiah] worked hard repairing all the broken sections of the wall and building towers on it. He built another wall outside that one and reinforced the supporting terraces of the City of David. (2 Chronicles 32:5)
The wall rising just beyond the grass is the wall of several structures that were built outside of 8th century Jerusalem.