Osgiliath, once the capital of Gondor, has been ravaged by the war with Sauron and suffers from a bad case of entropy. The best way to represent this in SC4 is to lower funding for City Beautification and let the game run for a few months. Unfortunately, doing this applies the effect to everything else on the map, so it looks like a small, flat Minas Tirith if you open the city in your game. Youy can, of course, lower the funding and run the simulator yourself to get the look in the bottom two screenshots.

Interestingly, and probably obviously, this city was built the same way much of Peter Jackson's' Osgiliath was built - Minas Tirith buildings were modified a little and "weathered." In this case, I also had to rename them.

The first screenshot below is just an image of an earlier version of Osgiliath being bulldozed that I wanted to throw in here.

If you have created any lots or buildings related to Osgiliath, please send them to globalfiles@simglobal.net, and I may include them in a future version of it.