Grab some extra tires laying around and slap it on some wood and have your kids have a nice little 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.
Frugal Fun for Boys
cheap obstacle course ideas - Google Search
Owens 5th Birthday
Old Man Johnson, Inc. - obstacle course
DIY Garden Obstacles - I'm thinking drill holes in a top bar of pvc and attach water hose so kids have to jump over a spray of water.
Pool noodles for obstacle course - for Wipe Out party
Supernova Jungle Gym Accessories & Hardware Kit
DIY wood zig-zag balance challenge #kids #backyard #playscapes
for the little ones
Make A Kids Obstacle Course | Obstacle course