How about a completely underground one? Like if it was in a large, closed off underground cave. It could have stalactites and stalagmites, and have a maze of tunnels leading to random places. Of course there would still be a large, open area for general skiing, but i think the stalactites/stalagmites would make people think about their skiing more, and the tunnels would just be really fun. The bases can be suspended by what looks like an old mining rig, so that way the tunnels wouldn't make it so easy. I dunno how hard this would be from a coding stnadpoint however...