Ontario, the second largest Canadian province, is the most populous and the leader in mineral, industrial, and agricultural output and in financial and other services. It is bounded on the N by Hudson Bay and James Bay; on the E by Quebec; on the S by the St. Lawrence River, lakes Ontario, Erie, Huron, and Superior, and the United States; and on the W by Manitoba. The province has three main geographic regions. Western and central portions lie on the Canadian Shield, a region of mineral-rich rock but very little arable land, covered with forests and broken by a labyrinth of rivers and lakes. In the north the Hudson Bay Lowlands border on Hudson and James bays, an area consisting mainly of marshes, swampland, and forest. In the south and east are the Great Lakes–St. Lawrence lowlands, where nine tenths of the population live and where industry and agriculture are concentrated.
The far north has subarctic conditions, while the west has a temperate climate. Around the Great Lakes the weather is moderate and summers are longer than in other parts of the province. The St. Lawrence River and seaway give Ontario access to the Atlantic. Other important rivers include those on the province's borders—the Ottawa (which forms part of the boundary with Quebec), and the St. Clair, the Detroit, and the St. Marys, all on the U.S. border. Several of the province's rivers are used to generate hydroelectric power, among them the Niagara, with its famous falls. Besides the falls, Ontario has numerous other tourist attractions, including the annual Shakespeare and classical repertory theater festival at Stratford, the annual George Bernard Shaw festival at Niagara-on-the-Lake, four national parks, the huge Algonquin Provincial Park, and numerous lake and island resorts.
With steady immigration from Italy, Germany, Portugal, the West Indies, India, and East Asia, Ontario's ethnic composition is rapidly diversifying. People of British ancestry make up about half the population, and one tenth are of French extraction. Over 80% of Ontario's residents live in urban centers. Toronto, the largest metropolitan area in Canada, is the capital; other important cities are Ottawa (the capital of Canada), Hamilton, Kitchener, London, Windsor, Thunder Bay, and St. Catharines.