Along the crest of the Santa Cruz Mountains, Castle Rock State Park embraces 3,600 acres of 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 popular with rock climbers. The forest here is lush and mossy, crisscrossed by 32 miles of hiking and horseback riding trails. These trails are part of an even more extensive trail system that links the Santa Clara and San Lorenzo valleys with Castle Rock State Park, Big Basin Redwoods State Park, and the Pacific Coast.