So I have been working the west part of my downtown in my oldest city. The main buildings are office buildings, a mall (not finished), grand Hotel and so much more. I am also happy with the new city hall train station which will be the 2nd biggest in the game.
I hope you like it, I took some screen shots of the unfinished mall and the buildings ofc. Also included a office building. The downtown has a subway system underneath it and it also has a unground mall as well as a sewer system.