Plitvice Lakes National Park

Plitvice Lakes National Park, established in 1949, ranks among Croatia’s oldest and largest protected areas. It earned a spot on the UNESCO World Heritage list in 1979 due to its striking sequence of tufa lakes, caves, and interconnected waterfalls. Situated in the mountainous karst region of central Croatia, the park sits along the border with Bosnia and Herzegovina. Covering 296.85 square kilometers (114.61 square miles), roughly 90 percent of this territory lies within Lika-Senj County, while the remaining 10 percent falls under Karlovac County. A major north–south road running through the park links Croatia’s interior to the Adriatic coast.

The park’s lakes form a cascade, with sixteen visible at the surface. Their colors—ranging from azure to green, gray, or blue—shift constantly based on mineral and organism content in the water and the angle of sunlight.

The name “Plitvice” first appeared in a 1777 document by Dominik Vukasović, a priest from Otočac. It derives from natural processes that shaped shallow basins (in Croatian, *pličina*, *plitvak*, or *plitko* meaning “shallow”), which then filled with water. Over centuries, water has altered the limestone landscape, and growing travertine barriers have slowed and held back the flow, continuously rising in height.

The park spans two counties: Lika-Senj (90.7 percent) and Karlovac (9.3 percent), so its authority operates under national jurisdiction. The total water surface area is about 2 square kilometers (0.77 square miles). The two largest lakes, Prošćansko jezero and Kozjak, account for roughly 80 percent of this water area and are also the deepest, at 37 and 47 meters (121 and 154 feet) respectively. No other lake exceeds 25 meters (82 feet) in depth. The elevation drop from the first to the last lake is 133 meters (436 feet).

Water availability, shaped by terrain, heavily influences the area’s biodiversity. The park is ringed by mountains: Mala Kapela to the west and Lička Plješivica to the east, which also marks the border with Bosnia and Herzegovina. The park lies on the Plitvice plateau, surrounded by three peaks of the Dinaric Alps: Lička Plješivica (Gola Plješevica at 1,640 meters), Mala Kapela (Seliški Vrh at 1,280 meters), and Medveđak (884 meters). Forested mountain slopes act as water reservoirs and provide refuge for many animal species. The steep altitude difference within a narrow corridor—from the southern mountains to the Korana River in the north—is a key factor for the region’s biodiversity. The overall elevation range within the park is 912 meters, from Seliški vrh at 1,279 meters down to 367 meters at the bridge over the Korana River.

The Plitvice Lakes begin in the park’s south, where the Bijela Rijeka (“White River”) and Crna Rijeka (“Black River”) converge. These rivers originate south of the municipality of Plitvički Ljeskovac and meet at a bridge in that village. From there onward to the lakes, the water is called Matica (meaning “water current,” “root,” or “origin”). At Liman Bay (also called Limun), part of Prošćansko jezero, another small river fed by permanent springs flows in, though its water volume varies. Temporarily, water from usually dry creeks reaches Prošćansko jezero from the west.

Tufa sediments have formed since the Pleistocene in sinkholes and depressions between the surrounding mountains. The park’s underground can be divided into two zones: the Upper Lakes in the south, underlain mainly by dolomite rock, and the Lower Lakes in the north, underlain mainly by limestone. Dolomite is slightly harder than limestone and less permeable to water, while limestone is more compact and massive but allows greater water flow.

Average annual precipitation at the lakes is 1,500 millimeters (59 inches), with the heaviest rains in spring and autumn. Relative humidity averages 81.8 percent. January temperatures average 2.2 °C (36 °F), while July and August average 17.4 °C (63 °F). The overall annual average temperature is 7.9 °C (46 °F). Snow falls from November through March, and the lakes typically freeze over in December and January.

The lakes result from centuries of chalk sedimentation in this karst environment, forming deposits called tufa or travertine (known as *sedra* or *tuf* in Croatian, among other names like *bigar* or *vapneni mačak*). Geologically, the processes shaping the lakes are relatively young. The complex dissolution and sedimentation of limestone require specific climatic conditions, which have existed only since the end of the last ice age, roughly 12,000 to 15,000 years ago, according to tufa evidence.