The headlands combine lovely rolling hills and ocean views with the crumbling remains of the concrete defenses set up to protect the San Francisco Bay during WWII. Just a few miles from the city, you'll find fantastic views of magnificent cliffs that go for miles and miles. You'll need a car to get out here, but you'll find the trip to be more than worth it.
Here's a lesser known gem. Pinnacles National Park is the newest national park in the country (officially established just a few years ago) and is built around a set of massive rocks and ridges that climb up out of California's central valley. If you can manage the 4 mile hike to the top (which is more difficult than it sounds because of elevation), you'll be rewarded with expansive views and deep red rocks. You might even spot a condor.
This peninsula is a favorite for road trips, camping, and beach combing. While it's more like a Northwest beach than one for sunbathing (expect fog), you'll still love its stark beauty. In this small stretch of land, you'll find rolling landscapes, old ranches, rows of cyprus trees hanging over ancient roads, and even a waterfall that dumps out straight onto the beach.
This strange site is practically right in the middle of San Francisco. In additions to the crumbling remains of an old bathing complex, you'll find fantastic views of the Pacific Ocean crowned by Eucalyptus Trees.
This mountain dominates the southern part of Marin's peninsula. It's popular amongst campers and bicyclists, but it has plenty to offer the landscape photographer too. In particular, you should check out the Dipsea Trail, the Bootjack Trail, and the road to the summit for great 360 degree views of San Francisco, the East Bay, and the ocean.