Central Massachusetts encompasses Worcester County, which is hilly and rocky. It features the urban city of Worcester, and the smaller cities of Fitchburg, Leominster, Gardner, and Southbridge. Central Massachusetts also includes many rural hill towns, forests, and small farms. The geographic center of Massachusetts is in the town of Rutland, in central Worcester County.[http://www.infoplease.com/ipa/A0108225.html] The Quabbin Reservoir (formed by the dammed Swift River—a former Connecticut River tributary), borders the western side of the county; it is the main water supply for Greater Boston.