Going to Austin for a music festival this April. I have one free day while I'm there, what should I do for fun on that free day?
40 miles south of Austin is New Braunfels, home of Schlitterbahn, a very large family-owned water park (I think it may be the world's largest, actually). It regularly gets all sorts of amusement industry awards for best water park and so forth, and is more-or-less the only water park that can compete with Disney water parks on their level.