I had a blow up pool for grandkids on my deck - just 5 feet diameter, and Mr. Darcy would go in to 'rescue' the rubber duckies! Now this summer I got a 6-1/2 diameter pool with rigid sides, although they are kind of floppy, they are too tall for Mr. Darcy and Lizzie to get into, so I am debating getting another small pool for them, or a little stool so they can get in bigger pool - I know they can jump back out of it.