Henry Cowell State Park in Santa Cruz California, is a great place for a hike through some old redwoods to the San Lorenzo River. All trails are open to hikers.
Along Big Sur's rolling Pacific Coast you will find the Julia Pfeiffer Burns State Park. Famous for it's beach front waterfall, hiking trails, and scuba diving.
The Russian Gulch Waterfall is just a short hike from the beach at Russian Gulch State Park. The park is just north of the town of Mendocino off Highway One.