playground

Good morning all, I’m about to complete on a house with a garden big enough to-build a tree house for my kids. The problem is no trees! Ha. I’m looking to build a play house with a suspended floor about 6ft off the ground with a room underneath. I just need advice on timbers etc. I would like...

Is there a name for the kind of timber posts you see in playgrounds that follow the natural shape of branches, just smoothed and filled? I'd like to buy some for a garden project but not sure what to google!