I recently learned some fun facts about Niagara falls that I had not known. First of all, as amazing as it appears now, apparently the current flow of water over the falls is a mere fraction of what was witnessed by the first europeans to discover the falls. Between 50% and 75% of the flow is now diverted through huge tunnels to hyrdoelectric plants. Second, the falls are slowing moving upriver due to erosion. They used to recede an average of 3 ft per year until the major diversion was done in the 1950’s to produce electricity. They now recede around 1 ft per ten years. Learn more at Wikipedia.