The day we got to San Diego, we went to the beach. It was too cold to swim, sure, but since the kids have never really been to the beach, we figured they might enjoy walking along the shoreline.
The next morning we went to Sea World. That next evening we started our Disneyland shenanigans, yet I think that the best time the kids had was on the beach. They picked up shells. Nolan started digging a hole and soon after, they all joined in, even though the hole kept refilling with water and they were a muddy sandy mess as a result.
It was just like when they were toddlers, when the most exciting thing about the shiny new present was....the box it came in.