I remember going from the backyard tent phase to the tree fort phase, kids really do need their own place at times to feel free to play at what they want. I never had a playhouse or club house as the boys would call them, but built plenty of tree houses and forts as a kid.
I always wanted a treehouse, but never was able to build one. We used to build forts for when we had pine cone fights though :)
My grandad was a brilliant woodworker and I wish I had been older to learn from him before he passed.
I was lucky growing up the guy that owned the land across from where we lived did not care how many tree forts were built or how many holes were dug, There were oak trees, the best for fort building and free grapes and almonds during the right season. Sling shot and almonds make a big clang when they hit the garbage can lid shield.
Sounds like good times.
One brother and I invented a night variation of pine cone fights - which was two was a battle with teams on either side of a field and campfires to light the pine cones. We played a couple times until our mum saw that our clothes had burn holes through them :)