I love gears of war, and for my interior space and worlds class I decided to create a location from the gears of war series not used in a game. Lakar is what I decided to go for, since I found reference photos of it:
Rather than grab static meshes from UDK, I decided to model and texture my own assets, which took a lot of my time. I also regret not using UDKs terrain features. The sharp transitions from concret to grass doesn't look good at all. I also discovered that the first gears of war game for PC comes with an editor allowing you to create your own levels. This was exciting, and turned out to be a HUGE distraction.
Screens from the gears editor: