We built a small one just for playing around. We used the outdoor green carpet and boxed it in with landscaping timbers. My husband used some kind of plumbing joint for the holes, with a wide hole on one side and a smaller hole at the other end. We cut holes in the carpet and sunk the plumbing into the ground and then put rocks into the hole for the ball to land on. Used glue to attach the carpet edges to the hole. We put a few "obstacles" around, a large rock, a small lighthouse statue. Its not nearly as pretty as the pictures in the post above, but the kids enjoy messing around with it.