We drove up to the summit of Mt. Diablo which is located east of Berkeley and west of Brentwood, CA. We took the short hike up North Peak Trail to another lookout point. Most of the trail from the beginning is down hill so make sure you pack some good hiking boots. Once you past Gap Fire Road it's an uphill climb to the peak where the last 100 ft is fairly steep. As the highest peak in the Bay Area, on a nice day you get an awesome view all around. The day we were there it was a bit hazy but we still had some great views especially out to Livermore. Near the Summit Visitor Center, the area was infested with some sort of flying bugs so not the best place to have lunch despite the many picnic tables. With hardly any shade on this trail, we would not recommend coming during summer.