Unless some local shows you, you will never know which place is his. I did not, although having ridden my bike past many times. Had it pointed out from the top of one of the local hills years later.
To the best of my recollection Hidden Valley is a wealthy enclave in Thousand Oaks - and not too far from the Reagan Library.
I live about 30 miles east of there, but there are a lot of actors and writers in my neighborhood, too. It’s not nearly as conservative, though. Sigh.