Between our travels last year I built this split-level tree
deck for the grandkids. The lower level is at 5' and the upper
level is at 10'. The lower level is built on the frame of what
was the "Fort" - a playhouse for our kids I built in the 80's.
It was an enclosed house with windows, a door, and a trap door to
"escape". Unfortunately, spiders and wasps seemed to enjoy it
too much so it had to go.
This year I added some playthings - a slide,
climbing rope, some swings, and a firemen's pole. The kids wanted a zip-line
to the swimming pool but I think that's a bit much.