I modeled the structure and the cliffs with plane modeling, then the outside sniper base with box modeling. The ground was just filled in with triangles that fit between the two buildings and the manhole. There's no coplanar faces there or anything. I've only got two errors on my map; a few degerenate triangles inside that don't really matter because you can't see them and they don't make any difference.
Here's lightmaps on super. As you can see, there's still odd black surfaces where there shouldn't be. Some parts of the surface are lighter than other areas, or darker than they should be.
http://img401.imageshack.us/img401/8885/capturetf3.png