also called  Antarctic Archipelago,  island group off the northwestern coast of the Antarctic Peninsula, from which it is separated by Gerlache and Bismarck straits. The archipelago, which includes the islands of Anvers (46 miles [74 km] long by 35 miles [56 km] wide), Liège, Brabant, and Wiencke, was discovered in 1898 by the Belgian explorer Adrien de Gerlache. Argentina and the United Kingdom have operated research stations in the islands, which are claimed by both these countries and Chile.