There are numerous mods for Cities: Skylines, ten of which we featured right here on our list of the ten best mods for the game (at the time).
One mod, which didn't make it onto the list that was released more recently is the Isometric Camera mod. Developed by a modder named Ulysius, the mod locks the camera to an isometric viewpoint, making the game look a lot like SimCity 2000, SimCity 3 and SimCity 4–all of which were locked to isometric views for reasons both technological and aesthetic.
The description reads: "Changes the camera to isometric, just like the citybuilders of old!"
To activate it, just find it in the F8 menu once it's installed.
It's important to note that the mod does obviously not work with other camera mods like the first-person one.