It is Canada's most populous province by a large margin, accounting for nearly 40% of all Canadians, and it is the second largest province in total area. Ontario is fourth largest in total area when the territories of the Northwest Territories and Nunavut are included. It is home to the nation's capital city, Ottawa, and the nation's most populous city, Toronto. Ontario is sometimes conceptually divided into two regions, Northern Ontario and Southern Ontario. The great majority of Ontario's population and its arable land is located in the south. In contrast, the larger, northern part of Ontario is sparsely populated.
Ontario is bordered by the province of Manitoba to the west, Hudson Bay and James Bay to the north, and Quebec to the east, and to the south by the U.S. states of Minnesota, Michigan, New York, Ohio and Pennsylvania. All but a small part of Ontario's 2,700km border with the United States follows inland waterways: from the west at Lake of the Woods, eastward along the major rivers and lakes of the Great Lakes/Saint Lawrence River drainage system.