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
County island that is quickly filling up all available land for development. Other times, the real estate of a county island is owned by one or a small number of owners who live elsewhere, and have no interest in annexation, or who intentionally hold onto the land inside a growing metropolitan area for the interest of land value going up drastically. Because these patches of land are not incorporated into the city surrounding them, they usually fall under the jurisdiction of the county in which they are located. This can create problems if a county island is itself densely populated; they must