Alert, Nunavut, is a Canadian military base located at the north end of Ellesmere Island on rugged terrain surrounded by hills and valleys. The shoreline is composed of slate and shale while the offshore is covered with pack ice throughout the summer months. The site was first visited by Sir George Nares, who commanded HMS Alert in 1875-76, the first vessel to land on the shores of northern Ellesmere Island. In 1950, the Canadian government established a weather station at Alert. It was taken over by the military in 1958. The military continues to use the base year-round, but does not reveal the number of men or the technology present at the site for reasons of security. Access to Alert is restricted to military personnel. It is the most northerly permanent settlement in the world.