Los Encinos State Historic Park is located in Encino, CA. It really is just right in the middle of the city, taking up a couple of city blocks. On one side, through the orange trees, it runs into a grocery store parking lot. Yet, the park still manages to be a lovely, quiet, refuge from any city noise or bustle. We visited on a weekend day, and there were several families out letting their kids run around, feeding the ducks, and picnicking.
The adobe is open for free guided tours, but I think at this point they are by appointment only. However, the visitor center (in another of the buildings) is unlocked during regular park hours so that visitors can go look around.
Its just a nice park, a great place to go walk around on the weekend, and an interesting museum/visitor center. Currently its open Wednesday – Sunday from 10-5, but it would probably be best to check the website before you go.