bartlesville.

The Kiddie Park is in Bartlesville, Oklahoma.
It took us less than 3 hours to drive there.
We both said it would be a perfect little vacation for many of our friends.
The park is only open in the evenings, though.
I would recommend going on a weeknight if you can.
Friday night was a lot more crowded = more waiting in lines.

Drive down, find a hotel with a pool... it would be a perfect little trip!