Arctic Archipelago, Group of Canadian islands, Arctic Ocean. They lie north of the Canadian mainland and have an area of about 550,000 sq mi (1,424,500 sq km). The southeastern islands are an extension of the Canadian Shield; the balance consists of the Arctic lowlands to the south and the Innuitian Mountains to the north. The archipelago includes the large islands of Baffin, Ellesmere, Victoria, Banks, and Prince of Wales.