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 and the fourth-largest country by land area. Canada's sole border with the United States is the world's longest bi-national land border. The majority of the country has a cold or severely cold winter climate, but southerly areas are warm in summer. Canada is sparsely populated, the majority of its land territory being dominated by forest and tundra and the Rocky Mountains. It is highly urbanized with 82 per cent of the 35.15 million people concentrated in large and medium-sized cities, many near the southern border. One third of the population lives in the three largest metropolitan areas: Toronto, Montreal and Vancouver. Its capital is Ottawa, and other major urban areas include Calgary, Edmonton, Quebec City, Winnipeg and Hamilton.