I highly recommend Agate beach in Bolinas if you haven't gone. It's the home of Duxbury reef one of the largest shale reefs in North America.. Low tide reveals miles of tide pools that are 5x football fields in size. The pink Coraline covering the reef and all the cucs is amazing..I always see nudibrachs, huge sea urchins, small spiny lobsters, and baby octopus if your lucky!. The main tide pools are to the left and extend out for a mile or two at low tide. Or you can walk for miles to the right around the point to secluded beaches that have tide pools as well. Be mindful of the incoming tide times!! Or you may get wet returning..One tip!! take screen shots of the directions and map of location since some of the locals have a habit of taking down street signs to deter and confuse people lol been going on forever. Enjoy!!