Read what he posted. Those trees are actually a skybox, not individual models.
Anyway, I like the second one. The formation of the concrete structures is nice and reminds me slightly of a map in Killing Floor. I also appreciate the creative idea of using a real image of a forest as the skybox to serve as a nice background - I wouldn't have even thought of that! So good job. Looks nice. My main issue is the tiles. They look very... scribbly/messy and I think they don't really tile so well. The shadows near the bushes probably isn't such a good idea either, since the shadows are very solid while the bushes are not, if you get what I mean.
Also, the building looks like it's floating above the hills and foliage on the far left. Fix that!