Norfolk is a county in East Anglia in England. It borders Lincolnshire to the west and north-west, Cambridgeshire to the west and southwest, and Suffolk to the south. Its northern and eastern boundaries are the North Sea and, to the north-west, The Wash. The county town is Norwich. With an area of and a population of 859,400, Norfolk is a largely rural county with a population density of 401 per square mile. Of the countys population, 40% live in four major built up areas: Norwich, Great Yarmouth, Kings Lynn and Thetford. Norfolk was the most populous English county until the Industrial Revolution. The Broads is a network of rivers and lakes in the east of the county, extending south into Suffolk. The area is not a National Park although it is marketed as such. It has similar status to a national park, and is protected by the Broads Authority.