You don't need to get out the city for a nice, leisurely hike. The Land's End trail (part of the Coastal Trail), located in the Outer Richmond district of San Francisco, is as good as any beginner trail in the Bay Area. You get the bonus of some incredible views of the Golden Gate Bridge, access to beaches, beautiful trees, and more.
Here are two pairs of wallpapers from the Land's End Trail and Coastal trail. Both are available at both 3360x1050 and 3200x1200 and have a only a single stitch line placed directly at the monitor split.
Land's End Trail / Coastal Trail - very cloudy:
3200 x 1200:
Land's End Trail / Coastal Trail - a little brighter:
3200 x 1200: