Harlem Valley State Hospital, south of the hamlet of Wingdale in the Town of Dover, was a New York State psychiatric hospital that operated from 1924-1994.
The grounds were originally slated to be a correctional facility, Wingdale Prison, but complaints by the local population caused a re-purposing of the buildings (under construction) into a state hospital. It is located on NY 22/55 opposite the Harlem Valley-Wingdale station on the Metro-North Harlem Line.
The hospital was closed in 1994 due to budget cuts.(Wikipedia)