The beauty of the Plitvice Lakes National Park in Croatia, increased in the second round of the New Seven Wonders of Nature. Waterfalls of Plitvice, Croatia National Park. It is one of the 20 most beautiful lakes in the world for the post 17. The park covers an area of 33,000hectares and includes 16 lakes in succession, connected by waterfalls.Plitvice is the oldest national park in Southeast Europa. The park also many caves of which only a small part is agibile.I lakes are formed by two rivers: the White River and the Black River, which flow into the river Korana. The waters of these rivers are rich in calcareous salts(mainly calcium carbonate and magnesium carbonate) dissolution of carbonate rocks that form the geological structure of sito.Questi salts precipitated by vegetation, forming layers of travertine, one sedimentary rock recently.