The one thing that we added to the backyard of our previous home – though not substantially – was a portable inflatable pool for the kids. It was large enough to accommodate half a dozen running and jumping 5 year olds but not too big that it swallowed up the entire backyard obviously. It was fun for the time we had it set up though.
We never went beyond that by setting up anything larger than that. It was a nice dream though – to have a backyard pool with all the accoutrements like deck chairs. I’d even thought about maybe having one of those pool cabanas where we could change into our swimming outfits without having to traipse in and out of the house.