The British Indian Ocean Territory (BIOT) or Chagos Islands is an overseas territory of the United Kingdom situated in the Indian Ocean, halfway between Africa and Indonesia. The territory comprises the six atolls of the Chagos Archipelago with over 1,000 individual islands. The largest island is Diego Garcia, the site of a joint military facility of the United Kingdom and the United States. The terrain is flat and low, with most areas not exceeding 2 metres above sea level. The climate is tropical marine; hot, humid, and moderated by trade winds. With the exception of one four-lane motorway, most of the islands in the territory have no roads of any sort. Diego Garcia has a short stretch of paved road between the port and airfield; otherwise most transport is by bicycle.