Hamilton Pool Preserve, outside of Austin, was amazing! One of the neatest places either of us have ever seen. The limestone canyon with a waterfall has stunning, clear-blue water. In the winter it cost $15/car. The water was too cold to swim (even though a few people did), but it is less crowded. We enjoyed the sound of the waterfall with just a few others. I’ve read that summertime is much different and reservations are required. Still, we’d love to go back when the water is warmer and we can swim out to the waterfall.