Scotland is part of the United Kingdom. The mainland of Scotland, covering the northern third of the island of Great Britain, is bordered by England 96 miles (154 km) to the southeast, otherwise to the north and west by the Atlantic Ocean, to the northeast by the North Sea and to the northeast by the sea Surrounded by the north. The Irish Sea in the south also includes more than 790 islands, mostly in the Hybrid Archipelago and the Northern Islands. Most of the population, including the capital Edinburgh, is concentrated in the central belt - the plain between the Scottish Highlands and the Southern Highlands - in the Lowlands of Scotland.