Since the weather was so nice yesterday, I spent a few minutes outside taking pictures. Here is the kids' treehouse. We built this over the past couple of summers. This is not a "story book" treehouse, but more of a "tree fort", which is what we called them as kids.
The first story has an easy-access ladder so that almost all kids, no matter how small, can get up there and have fun. The second story has a rope ladder that goes up to it, and is more challenging to get into.