That’s awesome max!!!!
While Jeff is correct on the concrete, my only concern would be effecting possible resale value of the house.
If you and your family feel you’re planted there, then go crazy. Potential of leaving, I’d make a decorative rock garden or something.
Just my thoughts.
Whatever you wind up doing will be fun!
It’s awesome having a home course.
As long as you build something you can remove it doesn't matter. I built an offroad dirt track with a big banked turn at my old house. When I bought this house I dismantled the track and turned the area back to a backyard.