D.C.
The laguna niguel community center (Crown valley) has great activities for kids. Wild child water play at the community center, music class, painting, etc... Horse viewing at Nellie Gail is fun. Zoomars petting zoo is a good way to spend a morning. LN and the surrounding areas have fantastic parks. Slides, swing, etc... most in AV are covered. LN not so much, but if you go in the early morning its a good time. Dana Point harbor is also a good way to spend an afternoon or weekend. Great tide pooling in Laguna, Dana and Corona del mar too. Check the community papers or moms groups too. A god resource is the library-reading hours at Barnes and Noble or the local tlibraries are fun for that age group.
Saddleback college also has a great swim program.
Good luck!