Storage for pool. Easy to build, I think the bottom would have more holes for water draining. Maybe staple some sort of screen inside the bottom also to keep small critters out and probably some casters or short legs to keep it off the ground.
How to build an Outdoor Storage Box on casters- step by step tutorial. Materials: sheet of quality pine plywood pre-primed trim board PVC quarter round trim galvanized utility hinges rubber wheel swivel casters rubber wheel swivel casters with locks