Unlike most buildings in downtown Minneapolis, there aren't any "skyways" connecting the city hall to the rest of the city. Since exterior alterations are not allowed for buildings on the National Register of Historic Places, tunnels were constructed instead. Public pedestrian tunnels connect the building to the Hennepin County Government Center under 5th Street, and to the U.S. Courthouse under 4th Street. There are also restricted tunnels for use by the sheriff connecting under 4th Avenue to the Hennepin County Jail and to the Government Center. The METRO Blue and Green light rail lines have a stop on the south side of the building: the Government Plaza station.