The UK, consisting of Great Britain (England, Wales, and Scotland) and Northern Ireland, is an island nation just off the coast of France. It lies between the North Atlantic Ocean and the North Sea, and comes within 35 km of the northwest coast of France, from which it is separated by the English Chanel.
The UK has a total area of approximately 245,000 sq. km and a coastline which measures about 12,429 km. The heavy indentation of the coastline helps to ensure that no location is more than 125 km from tidal waters. The only land border connecting the UK to another country is between Northern Ireland and the Republic of Ireland.
The UK landscape varies, ranging from the Grampian Mountains of Scotland to the lowland fens of England which are at or below sea level in places.
The UK is twice the size of New York State. England, in the southeast part of the British Isles, is separated from Scotland on the north by the granite Cheviot Hills; from them the Pennine chain of uplands extends south through the center of England, reaching its highest point in the Lake District in the northwest. To the west along the border of Wales—a land of steep hills and valleys—are the Cambrian Mountains, while the Cotswolds, a range of hills in Gloucestershire, extend into the surrounding shires.
Important rivers flowing into the North Sea are the Thames, Humber, Tees, and Tyne. In the west are the Severn and Wye, which empty into the Bristol Channel and are navigable, as are the Mersey and Ribble.
The mainland areas lie between latitudes 49°N and 59°N (the Shetland Islands reach to nearly 61°N), and longitudes 8°W to 2°E. The Royal Greenwich Observatory, in South East London, is the defining point of the Prime Meridian.