Whitewater Tennis Center. Tennis fanatics will feel right at home here with 12 professional courts including six red clay courts, four hard courts, and two Pro-Grass courts. The new Andy Roddick Kids' Courts are the first in the United States to feature USTA cutting-edge, shorter, 60-foot courts to give children a training ground for learning the game more quickly. 101 Horseshoe Bay Blvd., Marble Falls, TX. 830/598–2591. www.hsbresort.com. Free for guests of the resort, $10 for visitors. Call for reservations.