Mt Diablo is a large park (over 20,000 acres) to the south of Clayton, CA. The main attraction of the park is Mount Diablo (3,849 ft). On clear days, you may see large portions of San Francisco bay area with the naked eye. The park is criss-crossed by hiking trails allowing you to form long challenging loops.

Best Months to Visit: Avoid summers as all trails are in the open. In spring, the valleys are green and spring flowers abound. During some winters, you may see snow atop Mt Diablo.

Parking: $10 per vehicle in July 2010, payable at the entrance kiosk. However, there are several trail heads in Mt Diablo that require no parking fees. For example, the trailhead at Regency Drive in Clayton, CA, is free.