The 16 lakes of Plitvice Lakes National Park were formed due to thousands of years of geological activity. They are renowned for their beautiful crystal waters in a variety of blue and green shades, from turquoise to emerald and teal. The 12 Upper Lakes are larger and deeper than the four Lower Lakes. The panoramic train and boat rides in the national park, as well as the various walking and hiking trails, provide unparalleled scenic views of the lakes.