We're also getting a surf park (Nland) this year and have a ton of wake-boarding/cable parks.
An hour south we have Dripping Springs and Wimberley with Jacobs Well, Blue Hole, Hamilton Pool, Krausse Springs, etc. If you think Austin looks like the rest of Texas, here are some examples;
Hamilton Pool; http://yestotexas.com/wp-content/uploads/2013/07/hamiltonpoo...
Blue Hole; http://ww3.hdnux.com/photos/27/63/44/6240562/3/920x920.jpg
Greenbelt (twin falls); http://www.austinmonthly.com/Twin%20Falls.jpg
I'm breaking Austin rules by talking about these, but hey, I already own a house, so move on in and make my little house even more ridiculously valuable!
"It's like an oasis of dirty water in the sahara," a former Austinite once told me. I'm sure they were being hyperbolic.