“You want me to get on that and go down to where?” I wailed from high atop the Alberta Falls waterslide, looking down to an alleged pool that was well out of visual range. My 11-year-old granddaughter nodded with a look of both consternation and resignation that I tried very hard to take in stride. Such was my introduction to a vast array of unusual children’s activities that mesmerized the kid in me as much as they did Dalya, 14, and Mollie, 11, as we frolicked through Great Wolf Lodge in Williamsburg, Virginia. There are 18 such water parks nationwide. So much was going on at the water park that I didn’t know where to look: the pool basketball game, the lazy river, the wave pool, the kiddie pool, Fort Mackenzie—a 12-level interactive treehouse with a section of ascending interconnected rope tunnels leading to two winding slides—a surf simulator, and …