Canada is a nation in the northern piece of North America. Its ten areas and three domains stretch out from the Atlantic to the Pacific and northward into the Arctic Ocean, covering 9.98 million square kilometers (3.85 million square miles), making it the world's second-biggest nation by all out zone. Its southern outskirt with the United States, extending exactly 8,891 kilometers (5,525 mi), is the world's longest bi-national land fringe. Canada's capital is Ottawa, and its three biggest metropolitan zones are Toronto, Montreal, and Vancouver. All in all, Canada is meagerly populated, most of its territory region being commanded by woods and tundra. Its populace is exceptionally urbanized, with more than 80 percent of its occupants moved in enormous and medium-sized urban areas, and 70 percent dwelling inside 100 kilometers (62 mi) of the southern fringe. Canada's atmosphere changes regularly over its vast zone, extending from icy climate in the north to sweltering summers in the southern areas, with four unmistakable seasons.