Now usually referred to as the H. H. Richardson Complex, the hospital buildings were designed in 1870 in the Kirkbride Plan by architect Henry Hobson Richardson. The complex consists of a central administrative tower and five pavilions or wards progressively set back on each side, for eleven buildings total, all connected by short curved two-story corridors. Patients were segregated by sex, males on the east side, females on the west. The wards housed mental patients until the mid-1970s. The central administration building was used for offices until 1994.