I just recently moved from Los Altos across the bay to Newark, California. A straight shot to work with the added benefit of driving across the Dumbarton Bridge and starting my day with a beautiful sunrise on the water.
My first full weekend here I found the imporant places like Trader Joes and Target.
Ok, so I'm set!
Then on Saturday I ventured off to the Sunol Regional Wilderness, part of the East Bay Regional Park District.
This is a 6,858 acre wilderness that is shared by the park district and ranchers. 
It was a gorgeous day with many hikers out and about. I took the Canyon View Trail, it was an easy hike that led to the valley's "Little Yosemite" area. A small granite canyon with a stream and small water fall that I will be sure to go back to after a rain.
As mentioned, the land is shared with ranchers and the cattle share the trail with any that may walk through. 
This path was on the way back down the trail- the views were incredible. High cliffs that seemed to touch the sky. 
It was another beautiful day in California!Check out the East Bay Parks and the Sunol Wilderness at: http://www.ebparks.org/parks/sunol