The Plitvice Lakes are a national park in Croatia, situated at 44.85° N 15.62° E, in the Plitvice Lakes municipality, near the border with Bosnia and Herzegovina.
The lakes are situated on the eponymous Plitvice plateau, between the mountains of Lička Plješevica (Gornja Plješevica peak 1,640 m), Mala Kapela (Seliški Vrh peak at 1,280 m) and Medveđak (884 m). The sixteen lakes are separated into an upper and lower cluster formed by runoff from the mountains, descending from an altitude of 636 m to 503 m over a distance of some 8 km, aligned in a south-north direction. The lakes collectively cover an area of about 2 km², with the water exiting from the lowest lake to form the Korana river.
The Plitvice Lakes lie in a basin of karstic rock, mainly dolomite and limestone, which has given rise to their most distinctive feature. The lakes are separated by natural dams of travertine, which is deposited by the action of moss, algae and bacteria. The encrusted plants and bacteria accumulate on top of each other, forming travertine barriers which grow at the rate of about 1 cm per year.