See the Discovery Science Center in Santa Ana
I can't say there is a lot to see in Santa Ana. But if you're visiting the Orange County area, Santa Ana is in the midst of the various cities that are worth seeing such as Newport Beach, Huntington Beach, Anaheim or Buena Park. You may want to make it a point, especially if you have kids, to visit the Discovery Science Center. The entry price is not too expensive and will only take a few hours of your day. They have some interesting interactive science exhibits that are actually quite fun. See more info under my Things to Do tips!