I only discovered this location recently from an event I attended. The Chula Vista Nature Center is a living museum located on one of the few preserved salt marshes left on the Pacific Coast. To get in, you need to park right outside the preserve and one of their buses will drive you inside (they come by every 15 minutes). Once you enter the preserve, you are a greeted by a few sea turtles (donated by Sea World). Admission is paid upon entry and is only a few dollars. Some of the indoor features are typical of these types of centers, but what I found wonderful were some of the rare birds such as the U.S. Bald Eagle on the grounds. These birds are even more majestic in person. There is also a ray exhibit which allows you to touch the rays.
The biggest bonus was being able to walk on some of the paths in the marsh. The path is roped off and winds in and out. There are a couple site points near the ocean that are beautiful to sit and enjoy the view. I would recommend stopping by if you’re in the area.