NP PLITVICE LAKES
With its exceptional natural beauty, this area has always attracted nature lovers, and already on 8 April 1949, it was proclaimed Croatia’s first national park. The process of tufa formation, which results in the building of the tufa, or travertine, barriers and resulted in the creation of the lakes, is the outstanding universal value, for which the Plitvice Lakes were internationally recognised on 26 October 1979 with their inscription onto the UNESCO World Heritage List.
The national park is world-famous for its lakes arranged in cascades. Sixteen lakes can be seen from the surface. These lakes are a result of the confluence of several small rivers and subterranean karst rivers. The lakes are all interconnected and follow the water flow. They are separated by natural dams of travertine, which is deposited by the action of moss, algae, and bacteria. The particularly sensitive travertine barriers are the result of an interplay between water, air and plants. The encrusted plants and bacteria accumulate on top of each other, forming travertine barriers which grow at the rate of about 1 cm (0.4 in) per year.
The 16 lakes are separated into an upper and lower cluster formed by runoff from the mountains, descending from an altitude of 636 to 503 m (2,087 to 1,650 ft) over a distance of some 8 kilometres (5.0 mi), aligned in a south–north direction. The lakes collectively cover an area of about 0.77 square miles, the water exiting from the lowest lake forming the Korana River. The lakes are renowned for their distinctive colors, ranging from azure to green, grey or blue. The colors change constantly depending on the quantity of minerals or organisms in the water and the angle of sunlight.