Take a 2 liter soda bottle, poke holes in it. Attach to a garden hose. Toss over a tree branch and let hang for a kids water sprinkler. You can loop it over a tree branch and let kids bat it around for more watery fun!
I like this idea, maybe could use more shallow water tubs thought. A big rive-like pool for water play. Kids can crowd around both sides of the pool. Also can learn how things travel from one end to the other
Wall mounted ball run. This would be great for kids who are too young for the marble runs. Could be used as a music installation if there are movable obstructions in the pipe that make sound when a ball touches them
Top 27 Ingenious Ways To Transrofm Old Pallets Into Beautiful Outdoor Furniture