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.
A little recycle project my husband I made for our organic garden. All the wood is made with recycled wood fencing (the one shown behind the planter). We were tearing down this poorly built fencing from the previous owner and decided to reuse the wood!