City: Clayton Park: Mt. Diablo State Park
Seriously, this is a tough hike recommended for people in good physical condition and with some hiking experience. Expect to finish in 4-5 hours. The payoff? One unbelievable view and the chance to encounter wildlife in this low-traveled area of the mountain.
From Walnut Creek: From I-680, exit at Ygnacio Valley Road. Proceed on Ygnacio Valley Road to Clayton Road in Concord and turn right (east). At bottom of hill, turn Right at stoplight onto Marsh Creek Road. At 4-way stop, turn RIGHT onto MOUNTAIRE PKWY. Follow to the End.