text source: http://en.wikipedia.org/wiki/Niagara_Falls
The Niagara Falls are the most powerful waterfalls in North America.[1] These voluminous waterfalls are situated on the Niagara River, straddling the international border between the Canadian province of Ontario and the U.S. state of New York. The falls are 17 miles (27 km) north-northwest of Buffalo, New York and 75 miles (121 km) south-southeast of Toronto, Ontario, between the twin cities of Niagara Falls, Ontario, and Niagara Falls, New York.