niagara falls, horseshoe falls
The Canadian Falls are also known as Horseshoe Falls for its horseshoe-like shape. It is 170 feet high and 2,500 feet wide. The massive volume of water which flows over the falls comes from Lake Erie and flows down the Niagara River to Lake Ontario on its way to the St. Lawrence River and, eventually, the Atlantic Ocean.
Click on the image to see a larger version of this photo
Here is a photo of the complete breadth of the Canadian Falls.