треугольник

Trekanten (English: The Triangle) is a small lake in southern-central Stockholm, Sweden.With a small drainage area with no major feeders, Trekanten is located in a park furnished with an artificial bathing beach and various planted-out fish species. In the early 1980s, potable water was begun to be poured into the lake while water from the bottom of the lake was pumped out, operations resulting in a significant reduction in levels of phosphorus but which failed to affect levels of nutrients and oxygen depletion in bottom layers.