Essex is a county in the east of England. It is bounded by Suffolk and Cambridgeshire to the north, Hertfordshire to the west, Greater London to the south-west, Kent across the River Thames to the south, and the North Sea to the east. It has an area of 1,420 square miles (3,700 km2), with a coastline of 400 miles (640 km), and a population according to the 2011 census of 1,393,600. At the top level of local government are Essex County Council and two unitary authorities, Southend-on-Sea and Thurrock. Under the county council, there are twelve district and borough councils.