Cool idea for backyard obstacle course.
32 Of The Best DIY Backyard Games You Will Ever Play- backyard obstacle course.
could do bug obstacle course DIY American Ninja Warrior Backyard Obstacle Course - Five different elements. Build and re-build this obstacle course, and then it breaks down for storage. Storage ideas in the post.
32 Fun DIY Backyard Games To Play (for kids & adults!) this has some of the best outdoor ideas I've ever seen. Will be trying ladder bean bag toss and sidewalk/box board game