Castle Rock

Castle Rock in September Sun, originally uploaded by ParsecTraveller.

Castle Rock in Mt. Diablo State Park. This huge rock formation dominates the view along trails in the area.

Mt. Diablo is an incredible wilderness oasis in the heavily-populated San Francisco Bay Area. There are several endemic plant species found on the mountain, as well as rare animals. Mt. Diablo is a jewel of a park, and worth stopping by if you're in the area.