Chicago City Hall is a 10-story building that houses the official seat of government of the City of Chicago in Illinois. Adjacent to the Richard J. Daley Center and the James R. Thompson Center, the building that includes Chicago City Hall houses the offices of the mayor, city clerk, and city treasurer; some city departments; aldermen of Chicago's various wards; and chambers of the Chicago City Council on the west side of the building. The building's east side (called County Building) is devoted to the various offices of Cook County, including chambers for the Cook County Board of Commissioners.