There's a lake that's a perfect rectangle - Apparently.
Lake Silvaplana in Switzerland is a man-made lake that was created in the 19th century to provide hydroelectric power. Its unique shape is due to the surrounding mountains, which forced the designers to create a rectangular shape to ensure the water level remained consistent. Measuring 7.5 kilometers long and 1.5 kilometers wide, Lake Silvaplana is a remarkable example of human engineering in harmony with natural geography.