North America – Niagara Falls (United States, New York). City of Niagara Falls, located practically on the waterfall, fed not only by its energy, but also by income from the millions of tourists who annually visit this natural wonder. It is hard to imagine, but in 1969 the American Falls have been drained for several months – to strengthen the slopes and prevent erosion. And in January last year they were frozen for the first time after 1947.
