Castlewood Canyon State Park is a real treat, a bona fide hidden gem in the State Park System. Next time someone tells you that the plains are flat and boring, tell them to go check out Castlewood Canyon. Also, this is a wonderful Fall hiking option, while the entire state is searching for Aspen groves, you can get some real color in Castlewood Canyon without all the crowds. The park has 3 canyon loops, a great visitor's center, and is terrific for kids, but adults can find real adventure here as well. It is fair to say that this my favorite hiking spot in the plains near Denver.