The William A. Clark Mansion at Fifth Avenue, New York 1920’s
The house took up 250 feet on 77th Street and 77 feet on Fifth Avenue, more than any other rich man’s mansion on Fifth opposite the park.
There were 25 guest rooms with their own baths, and 35 servants’ rooms, with men’s quarters (to the east) and female rooms (to the west). There was also a Gothic library that was 90 feet long, featuring a beamed ceiling and an immense carved fireplace.
Here are some more photos: