The Metropolitan Heritage Museum occupies the city's original 1887 administrative building — a Romanesque Revival granite pile that served as city hall, municipal court, and tax collection office for nearly 80 years before a new civic centre rendered it redundant in 1963.

The building was saved from demolition by a remarkable 11th-hour campaign that saw 50,000 residents sign a petition delivered by horse and cart to the mayor's office — a piece of theatre still celebrated in the museum's 'Save Our Stones' exhibit. Opened as a heritage museum in 1969, the Metropolitan presents the social, political, and architectural history of the city with a particular focus on voices that official civic history has traditionally overlooked: immigrant communities, labour organisers, women reformers, and working-class neighbourhoods.

The museum also serves as the formal headquarters of the Society — the regional body responsible for coordinating heritage preservation across all member institutions and sites. The Society's administrative offices, archive, and council chamber are housed in the building's original aldermanic wing, and its governance meetings have taken place here since 1972.