Cornwall is a ceremonial county in South West England, bordered to the north and west by the Celtic Sea, to the south by the English Channel, and to the east by Devon, the River Tamar forming the border between them. Cornwall is the westernmost part of the South West Peninsula of the island of Great Britain. The southwesternmost point is Land's End and the southernmost Lizard Point. Cornwall has a population of 568,210 and an area of 3,563 km2 (1,376 sq mi). The county has been administered since 2009 by the unitary authority, Cornwall Council. The ceremonial county of Cornwall also includes the Isles of Scilly, which are administered separately. The administrative centre of Cornwall is Truro, its only city.