Found some lonely old ruins near South Beach. The SS Point Reyes is a quick stop just behind a small town supermarket on your way to the point. The Cypress Tree Tunnel is an even shorter stop right up against Sir Francis Drake Blvd.
I walked 3.5miles (7mi there and back) down South Beach. I went so far that the only footsteps out there were mine! I was going to touch the cliffs at the very end just to say I went all the way but I stopped within a quarter mile because there was a big fat seal lumping around on the sand (he's the dark thing on the beach in that last photo). I didn't get any closer than that because they're not just friendly little sea dogs. Anyways, I got rich collecting sand dollars—found 7 big ones still intact, some with barnacles still attached! ++Bonus points!