I didn’t have room in Mulholland, Mountains and Malibu for this obscure reference, but if anybody remembers the hilarious 1948 screwball comedy Mr. Blandings Builds His Dream House, the house-exterior set still stands at Malibu Creek State Park.
I’d read that the exterior, which typically for a movie looks to be about 3/4-scale, has been the park office for decades. And yes, it’s still there, right next to the campground.
Before it was a state park, Malibu Creek State Park was owned by 20th Century Fox and used for locations (although this wasn’t a Fox picture).
So while Cary Grant and Myrna Loy are long gone, their house is still there.