One of the most popular places in Austin to cool down and one of the most popular places regardless is Barton Springs Pool. The outdoor pool is filled with water from two natural springs: Barton Creek and Main Barton Springs. Because of the constantly flowing water of the springs, the pool is cooled down to 68 to 70 degrees all year long. Compared to most other public pools, food is not allowed inside Barton Springs Pool to keep the pool and grass area clean. The best times to visit the pool is either very early in the morning to have the water for yourself, or one hour before it closes to enjoy free entry.