Barton Springs Pool is a recreational outdoor swimming pool that is filled entirely with water from nearby natural springs. It is located on the grounds of Zilker Park in Austin, Texas. The pool exists within the channel of Barton Creek and utilizes water from Main Barton Spring, the fourth largest spring in Texas. The pool is a popular venue for year-round swimming, as its temperature maintains as stable 68 °F (20 °C) in the winter and summer.