The Northwestside, generally located north of the Grand River, with the city limits defining its north and western borders, is physically the smallest side of the city. This part of the city includes moderate-density residential areas and some green areas. North of Grand River Avenue, the main street of the side, lie warehouses and light industrial areas served by a major rail line that runs through Lansing. The most notable landmark of this side is Lansing's airport: Capital Region International Airport.