Lancaster is a town in Coos County, New Hampshire, USA, on the Connecticut River named after Lancaster, England. As of the 2000 census, the town population was 3,280, the second largest in the county after Berlin. It is the county seat of Coos County and gateway to the Great North Woods Region. Lancaster, which includes the villages of Grange and South Lancaster, is home to Weeks State Park and the Lancaster Fair. Part of the White Mountain National Forest is in the eastern portion. The town is part of the Berlin, NH–VT Micropolitan Statistical Area. The primary settlement in town, where over 51% of the population resides, is defined as the Lancaster census-designated place (CDP) and is located at the junctions of U.S. Route 3 and U.S. Route 2, along the Israel River.