For bird lovers, Hornsby Bend is a great place. It is located east of Austin at the water utility's biosolids treatment center. Nothing like it sounds! They have a great partnership with several groups such as Texas Parks and Wildlife, Travis Audubon Society, US Fish and Wildlife, and the list goes on and on. They have worked together to create a great natural area with hiking tails, and a bird blind on one of the lagoons. There are several lagoons with varying water depths, which draws a variety of birds. I was amazed the first time I went out! Worth the drive out if you enjoy seeing lots of birds. Great photo op.
http://hornsbybend.org/