fallen tree limbs to become a treehouse and play structure

Jeff and I went to inventory a pile of cut tree limbs. The client wants us to use the pieces of two trees in creating a new play structure/play area. To get started we numbered, photoed,and measured each limb and trunk. And I sketched each limb too as part of getting to know it. Now I'm going to try to figure out how to use them best.

The cut pieces are from a giant ash tree that had to be cut down (not sure why - sick or inconvenient?)The pile as-is is pretty fun - Jeff and I had a great time scrambling around it. But those limbs are so heavy we will need to make sure if we construct a log pile that the logs are actually attached to the ones below so that no log could ever roll and hurt someone.

The long fallen tree is an oak tree that fell over in a rain storm and just missed the house. I'm thinking of using it much like it is seen here, as a bridge in the play area. I'll clean off a lot of the small branches and we'll have to get the landscape crew to haul it with their heavy equipment to the backyard.

I got very sleepy after the inventory. Lots of possibilities but high degree of difficulty...I am going to have to sleep on this one for a while. I'll keep you posted as to our progress.