I've got 2 kids, 3 & 7, and we are often on a budget. Here are some fun things to do that cost little or nothing:
- Just north of Santa Monica is the amazing Noah's Ark by the Skirball museum. My kids LOVE this play structure and hate to leave. You do have to make an advanced reservation, and they do charge a fee, though: http://www.skirball.org/index.php?option=com_ccevents&...
- The Cabrillo Marine Aquarium in San Pedro is free. It's a bit of a drive from Santa Monica (about 40 minutes south), but by L.A. standards that's not much of a drive. Our kids really love this place. It has a whole exploratorium-type of room that is really fabulous. The beach is adjacent, and you could bring a picnic lunch since they have a beautiful park where you could relax and eat. http://www.cabrillomarineaquarium.org/
- The Science Center in downtown Los Angeles is also free. They have a lot of great hands-on exhibits, and they also have exploratorium type rooms for the little one. http://www.californiasciencecenter.org/
- Just next to the Science Center is the Natural History Museum. They do charge admission, but well worth it. Their dinosaur exhibit is under construction (just telling you in case he's a dinosaur fiend). But in June their live butterfly garden will be open, which is a fabulous experience. In the bottom floor of the museum they have an amazing exploring room where kids can dig for dinosaur bones and view live insects. http://www.nhm.org/site/
- In Pasadena they have a fabulous kid's museum. It costs $10 each to get in. It is super fun with all kinds of play activities. Just bring an extra set of clothes because they do have a bunch of water activities. http://www.kidspacemuseum.org
The beach of course is always a great free, fun day. There is the Santa Monica Pier, but the cost is kind of pricey. For that kind of money I'd spend a bit more and take him to Disneyland.
Hope that helps. Feel free to message me if you want some more info.
Take care,
B.