Canada is a country in the northern part of North America. Its ten provinces and three territories extend from the Atlantic to the Pacific and northward into the Arctic Ocean, covering 9.98 million square kilometres (3.85 million square miles), making it the world's second-largest country by total area. Its southern border with the United States, stretching some 8,891 kilometres (5,525 mi), is the world's longest bi-national land border. Canada's capital is Ottawa, and its three largest metropolitan areas are Toronto, Montreal, and Vancouver. As a whole,age of the Canada Act, bringing the Constitution of Canada fully under Canadian control, referred only to Canada, and later that year the name of the national holiday was changed from Dominion Day to Canada Day.[19] The term Dominion was used to distinguish the federal government from the provinces, though after the Second World War the term federal had replaced dominion.[20]