Thanks Grazr. I know what you mean, I'm not completely satisfied with the fence at the moment - I might make it like the second picture in the thread: a raised mound with the fence on top, so it's a bit higher. Also I'm going to extend the B building a bit, so you won't hit an invisible wall when you're on the roof.
Anyway, here are a couple more pictures. As I said, I'm really just picking random parts of the map at the moment.
Need to fix some of the prop fade distances, such as the ladder on B.