Apparently this was one of at least two publicity photos taken by John D. Kalodner in 1975 in New York City.
johnkalodner.com/photos/artists/1970s/eltonjohn_robertplant.jpg
johnkalodner.com/photos/artists/artists_1970s.html#top
^Impressive photos! Thank you for posting them.
information-britain.co.uk
It also has a hospital nearby.
abandoned-britain.com
Horselunges Manor, Hellingly
britishlistedbuildings.co.uk