I've done a bit of level design and mapping in the past (UT2004 and Quake 3 games). The most recent thing I did was a map of Hatshepsut Temple (Egypt) for a game development course last year. Here are some non-final (about halfway done) screenshots of it:







I also have a whole slew of reference images and design blueprints that my partner and I collected and worked on together. I mapped/modeled everything but terrain. I'll see if I can find my screenshots of the final version with terrain.

Edit: think I found them...























I did everything else but the modeling of the terrain and the rocks (rocks isn't accurate or the front half of the terrain. Everything else but the addition of weapons and spawn items is as accurate as I could make it to the real Hatshepsut Temple (of course to scale). Drawing and planning the blueprints from version 1 through 8 was probably the most headaching part. The frequent crashes of the Unreal Editor prolonged the time it took for me to actually make the darn map. Matt's (my partner) work on the terrain and rocks in Maya were considerably faster than my mapping (even with reuse of brushes).