I'm often asked what there is to do with kids at the coast. My kids love the beach. We have beach supplies in the garage. Doran Beach because it's in an inlet is calmer than the other coastal areas in Sonoma County. That being said...NEVER turn your back on the surf as you never know when a sleeper wave will appear. Doran has a nice flat beach surface. You can see it at high and low tides. This gradual surface makes it ideal for kids/families as no sudden drop offs unlike say Portuguese Beach. The waves are calmer as well in this area. I always liked that the Coast Guard as well is stationed just behind the Doran beach area. You can see them sometimes doing maneuvers or rescuing kayakers who have a gotten bit too far out after the wind has picked up.
There is a playground located adjacent to the Clubhouse area. You can get to it from the beach path off Gull Drive. The scenery can't be beat and the stairs lead to the beach as well.
Walking along this route...go Left at stairs on beach and you'll see a grouping of large rocks. Go at LOW tide as when HIGH tide comes in you can be cut off and have to take one of the Gulch trails back to Gull Dr. There are shallow cave formations and lots of rocks to look at with starfish, etc attached. Fun for kids. Going Right at bottom of stairs is the Doran Beach area. It's about 2 miles of flat beach. The WEST end is the camping area and jetty where you'll see crabbers and fisherman. The boat launch is in this area as well as picnic tables. There are two sets of bathrooms...one at the end where jetty is and another at the half way mark. I've seen countless seals walking along the beach and from March-May can see pods of whales swimming off coast as well as breaching the water.
The Children's Bell Tower is a short drive off CA-1 in Bodega Bay. The tower is a unique memorial to the memory of Nicholas Green. The hike is about a mile long. On a windy day you can hear the Bells ringing. The plaque tells the story of Nicholas and the generosity of he and his family.
Check website for opening data. The woods were shut down for a time for rejuvenation after the Sonoma County fires. I believe portions of the woods have now opened back up. HUGE majestic redwoods. Great short and longer hikes. Picnic area for lunches.
Zipline through the Redwood Forest. This was such a fun excursion. A group of five of us did this and then enjoyed lunch in Occidental. Check website for reservations/ages/etc.