The British Isles is a group of islands off the northwest coast of continental Europe comprising Great Britain, Ireland and a number of smaller islands. There are two sovereign states located on the islands: the United Kingdom of Great Britain and Northern Ireland and the Republic of Ireland. The group also includes the crown dependencies of the Isle of Man and, by tradition, the Channel Islands, although the latter are not physically a part of the archipelago. There are other common uncertainties surrounding the extent, names and geographical elements of the island group.
The term British Isles is controversial in relation to Ireland where its use is objected to by many people and by the government of the Republic of Ireland. Its use is also avoided in relations between the governments of the Republic of Ireland and the United Kingdom, who generally employ the term these islands.
The islands extend from Les Minquiers Reef, Jersey in the south (or Pednathise Head, Isles of Scilly if the Channel Islands are excluded), to Out Stack, Shetland in the north; and from Tearaght Island, Ireland in the west, to Lowestoft Ness, England in the east. There are more than 6,000 islands, amounting to a total land area of 315,134 km² (121,674 square miles).
Much of the British Isles is low lying and fertile, although there are mountainous areas in all regions except southern England and East Anglia. The islands are characterised by an unusually temperate climate for their latitude, due to their location in the Gulf Stream. The regional geology is complex, formed by the drifting together of separate tectonic plates and subsequent orogenic, glacial and weather erosion.