The United Kingdom is a sovereign state located off the north-western coast of continental Europe. With a total area of approximately , the UK occupies the major part of the British Isles archipelago and includes the island of Great Britain, the north-eastern one-sixth of the island of Ireland and many smaller surrounding islands. 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.