These simplified stripes represent massive retaining walls. The subdivision I'm looking at is essentially built on terraces, into the side of a hill. Wellington hills are made of clay, and retaining walls like this are necessary to prevent landslips. Mind you, you see houses hanging off the side of cliffs at all angles in this city, and some of them have been there for a hundred years.
This is where I used the cadmium red I talked about last time. The retaining walls are brownish coloured with red undertones, but not that bright in real life. Bright red looks nice on the canvass though and does a good job of highlighting the vertical elements of the retaining walls. I'm also finding that the accent colours I use have to be quite bright to compete with the chrome paint.
Using contrasting textures also helps to emphasise the structures' vertical elements, but they're all made entirely out of paper cubes, just like the original Menger sponge I made.