Ha Long Bay, in the Gulf of Tonkin, includes some 1,600 islands and islets, forming a spectacular seascape of limestone pillars. Because of their precipitous nature, most of the islands are uninhabited and unaffected by a human presence. The bay is famous for its scenic ocean karst topography and is often included in lists of natural wonders of the world. "Ha Long" means "Bay of Descending Dragons", though prior to the 19th century this name was not recorded in any document or archive.