Borough of Berwick-upon-Tweed Borough of Berwick-upon-Tweed Berwick-upon-Tweed was a local government district and borough in Northumberland in the north-east of England, on the border with Scotland. The district had a resident population of 25,949 according to the 2001 census, which also notes that it is the most ethnically homogeneous in the country, with 99.6% of the population recording themselves in the 2001 census as "White". It was also the smallest district in England with borough status, and the third-least densely populated local government district (after Eden and Tynedale). Its main town is Berwick-upon-Tweed, sited immediately to the north of the Tweed estuary. The
County (United States) Atoll, Kingman Reef, and Navassa Island. The remaining 3 islands in the U.S. Minor Outlying Islands have small non-permanent human populations. The least populous county-equivalent with a permanent human population is Swains Island, American Samoa (17 residents). The most densely populated county or county-equivalent is New York County, New York (coextensive with the New York City Borough of Manhattan), with 72,033 persons per square mile (27,812/km) in 2015. The Yukon-Koyukuk Census Area, Alaska, is both the most extensive and the least densely populated county or county-equivalent with 0.0380 persons per square mile (0.0147/km) in 2015. In the 50 states (plus