The National Center for Atmospheric Research offers plenty of ways to expand your brain while exercising the other muscles in your body. Noon tours on most Mondays, Wednesdays and Fridays provide primers on atmospheric science and current NCAR research, and free tablets loaded with audio, videos and additional content are available as well. Visitors can also conduct self-guided tours of the facility's sprawling campus; our favorite jaunt is the Walter Orr Roberts Weather Trail, which offers signage explaining wind, cold fronts, climate zones and even the notorious brown cloud along a nearly half-mile loop. But you don't need a weatherman to tell which way the wind is blowing: All of these options are free.
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