Lake Vrana is the biggest natural lake and of the largest wetlands in Mediterranean Croatia. It is two to five meters deep, and it is a cryptodepression – a geographical phenomenon where the surface of the lake's water is above sea level, and the bottom is below it. The narrow karst ridge is a natural barrier between the lake and the sea, but due to its porosity, the sea enters the lake waters and makes it salty.
The area of 57 km2 was declared a nature park in 1999.
The lake is considered an ornithological paradise, it is an ornithological reserve where over 100,00 waterfowl spend the winter. Due to the preservation of a large area of reeds and endangered wetland habitats, it is included in the list of important ornithological areas in Europe and on the Ramsar list of wetland habitats of international importance. From the hiding place, you can observe the life of birds, nesting and caring for the young – the entire life cycle. Vrana lake is part of the ornithofauna and so far 256 species of birds have been recorded, of which more than 100 nest in the area of the nature park.
Vrana lake is connected to the sea by the artificially dug Prosika channel, where the lake joins the Pirovačka bay. The canal was dug back in 1781 to prevent flooding of the Vransko polje. This has led to biological and ecological changes, and for all anglers the most popular change is the mixing of marine and freshwater fish species.
The lake is more than 13 kilometers long and has an area of about 30 square kilometers. Around the lakse there is a panoramic trail about 40 kilometers long, which is why it is a frequent choice for cyclists. A walk or drive to the viewpoint Kamenjak rewards you with a view of the lake and Dalmatian islands.