Castle Rock State Park is a state park of California, USA, located along the crest of the Santa Cruz Mountains. It embraces coast redwood, Douglas fir, and madrone forest, most of which has been left in its wild, natural state. Steep canyons are sprinkled with unusual rock formations that are a popular rock climbing area. The forest here is lush and mossy, crisscrossed by 32 miles (51 km) of hiking trails. Shown: a steep drop off with trees.