Kentucky Splash, right off I75, is ONLY a water park, but also has it's own campground, full hookups, right on site
Welcome to Williamsburg, Kentucky
KINGS ISLAND, between Cincinnati/Columbus,
and
KINGS DOMINION, n of Richmond VA
are both sister parks, and are excellent for families - easy walking, too
https://www.kingsdominion.com/
but, maybe the 'best', and FREE! entry(bring grammy and grandpa!),
is
KNOEBELS (pronounced "
K'nobles") in Elysburg, PA - just s of I80
and it has it's own CAMPGROUND, right on site...
https://www.knoebels.com/
been to all, and all are great : )