A UNESCO World Heritage Site, Plitvice Lakes National Park is one of the oldest national parks in Southeast Europe and the largest in Croatia. It has become is world-famous for its beautiful and vivid lakes, linked by a series of cascades and waterfalls. 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 lakes are renowned for their distinctive and ever-changing colours, ranging from azure to green, emerald or blue. Only one thing mars the spectacular beauty of the park - its rapidly increasing tourist numbers!