View looking south, and down on to a sunken garden in the Palace of Domitian. This is typically called the "Third Court." There was a pool in the center with a very unusual design in the center—of curvilinear shields. Water would have been where the grass now grows. A peristyle courtyard surrounded this rectangular pool.
In the very upper part of the image, note the people standing behind a fence. The view from there looks down on to the Circus Maximus and towards the Aventine Hill.