This clapboarded building, thought to be the country's oldest extant medical college building, was built for the Castleton Medical College (1818–1861), the first proprietary medical college in the United States and the most prolific grantor of medical degrees in the New England of its day. It included a first-floor lecture room, chemical laboratory, and library, and a second-floor dissecting room, anatomical museum, and skylit anatomical theater with ascending circular seating. These were housed in a building reminiscent of Federal meetinghouses, with a full-width pedimented vestibule joined by a cupola-topped tower to its gabled main mass. The vestibule is enriched with a trabeated door and three-part window framed by pilasters and dentil friezes, and the belfry has an elliptical arcade on swelling Doric columns. Moved twice and utilized for a variety of academic purposes, it was restored in the late 1960s to its 1821 form.