A few years ago we bought this rather silly Spongebob themed wading pool. It's at my mother's house and every summer we drag it out. It has held up fairly, though it seems to have a bit of a leak now and doesn't hold water for very long. However, it still provides hours of entertainment.
Even Sofia thought the pool was fun and loved standing next to it, occasionally reaching down to splash her hand in the water. None of the kids spent much time in the pool (it was only low 80s), instead the pool was viewed as a great place to refill water guns. You can see Nate in the picture with a big smile plastered across his face as he cradles his water blaster.
That rather silly pool turned out to be a good investment.