Lake Krn (also Veliko jezero or Jezero na Polju) is the largest high mountain lake in Slovenia and is one of the most important natural sights of the Triglav National Park. It lies in a hollow between Šmohorje in the southeast and Lemež in the northwest, formed by a glacier. The lake is 390 m long, 150 m wide and 17.5 m deep. The water level fluctuates by about 2 m, the highest level is in early summer. The bottom of the lake is covered with impermeable Cretaceous and marl rocks. There is a rich life in the lake, which is greatly endangered due to the large influx of nutrients. The lake is inhabited by Easter eggs and goldfish, which were introduced into the lake between the two world wars. Due to its extraordinary beauty and attractive surroundings, the lake is visited by many mountaineers and tourists. The first visits are recorded as early as 1312, when Bishop Henry III of Gorizia came here to hunt. It is of glacial origin and lies in the middle of the karst world (karst lake) below Krn (2244 m) and Batognica (2164 m), and in the narrowest part it is sandwiched between Lemež (2042 m) and Mali Šmohor (1939 m). Swimmers are a particularly big threat to him in the summer. Not far away is the Mountain Lodge by the Krn Lakes.