BK: O. M. G.
White Castle and West Castle. As a child of the Midwest AND Los Angeles, I totally know the score on this.
West Castle appeared out of nowhere one day. I want to say it was in the late seventies when I was living in Beverly Hills, because had I still been in Hollywood, I would have been at that one every day gorging myself. I remember it being on a southeast corner, and the ad says Las Palmas so I shan't argue with it. When I heard about it (it was on the radio -- some DJ or news person was getting a bag of them delivered) I was thrilled, and the first one I actually got to was the Van Nuys one which on that weekend afternoon (it might have been their opening week) was overrun with an enthusiastic crowd of White Castle fans. They had to have done great business for a while.
I never knew the Woodland Hills one, but I can tell you that the "coming" Long Beach one was on PCH just east/southeast of the big traffic circle. I was driving my parents around on one of their visits and we turned right in and had a meal there.
At some point I found them all gone, and I vaguely remember hearing it was because of White Castle. It's kind of too bad, because White Castle had NEVER expanded much past the Midwest (I think St. Louis and Minneapolis were about as far west as they went). Maybe if West Castle hadn't so blatantly copied everything...
I see on White Castle's website that they have something in Las Vegas now, but Vegas is always a unique situation for any company, and they still haven't expanded much beyond their original Midwest territory. Fortunately, I can get to a couple of them in the Bronx and in New Jersey. (There were rumors for a while about them being "just about to" come to Connecticut, but ... no such thing.)