John Muir National Historic Site, Mt. Wanda, & East Bay Trails
From the National Park Service page on the John Muir National Historic site on a sunny day.
A similar view dated March 2019 on a recent cloudy day, photo by author.
From the John Muir site, there is a trail leading to nearby Mt. Wanda. The photo below is from an article about Mt. Wanda at the exceptional RedwoodHikes.com site. 
Google Maps satellite view of John Muir Historic site area.
A map at the RedwoodHikes.com site has many other great East Bay and Bay Area hiking pages. A few are shown at the links below, but I recommend going to their site at the link above to see the entire Bay Area map with hot links to the various trails:
Mt. Diablo Foothills Tilden and Wildcat Canyon Regional Parks Redwood Regional Park Crockett Hills Regional Park Claremont Canyon Regional Preserve Wildcat Peak Nimitz Trail Briones Reservoir Las Trampas Regional Wilderness
Other sites: Oakland Magazine: Best East Bay Hikes