Northumberland role in the Industrial Revolution from the 18th century on. Many coal mines operated in Northumberland until the widespread closures in the 1970s and 1980s. Collieries operated at Ashington, Bedlington, Blyth, Choppington, Netherton, Ellington and Pegswood. The region's coalfields fuelled industrial expansion in other areas of Britain, and the need to transport the coal from the collieries to the Tyne led to the development of the first railways. Shipbuilding and armaments manufacture were other important industries before the deindustrialisation of the 1980s. Northumberland remains largely rural, and is the least-densely populated county in England. In recent years the county has
Polk Township, Monroe County, Indiana the National Register of Historic Places. According to the 2010 census, the township has a total area of , of which (or 88.06%) is land and (or 11.94%) is water. (This list is based on USGS data and may include former settlements.) The township contains these four cemeteries: Burgoon Church, Hillenburg, Mitchell and Todd. Polk Township, Monroe County, Indiana Polk Township is one of eleven townships in Monroe County, Indiana, United States. As of the 2010 census, its population was 360 and it contained 195 housing units. It is one of the least densely populated townships in the state; this