Here's a (very) quick study for the plaza... It's supposed to be the buildings that surround the plaza :

Study plaza.jpg

Tell me if it's obvious or not : I attempted to represent two rows of columns. One that support beams, the other that supports a roof. This roof is leaning on a long building (that goes all around the plaza, as well as the two rows of columns) The building is higher than the rool and the columns, and at the top of the walls of the building is a crenellation

Between my bad english and my bad drawing, I'm not sure anyone can understand anything...