It could be a gold mine for tourism, but tourists are not allowed near it. This is understandable, as lives depend on it.
The Croatian island of Cres captivates visitors at first sight with its wild beauty and nearly pristine nature. Rocky landscapes, dense forests, ancient villages perched on cliffs, and hidden bays with some of the most beautiful beaches in Europe often appear on postcards and tourist brochures. But, behind those images is something very different, a place that is not a tourist attraction, but a matter of survival.
This is Vransko Lake, a natural phenomenon that plays a key role in the water supply not only for Cres, but also for the neighboring island of Lošinj. The lake is unique in its features: its surface lies above sea level, while its bottom descends up to 60 meters below sea level. It was formed in a karst basin and shaped over millennia through complex geological processes, Metropolitan reported.
Protected Natural Resource
The water in the lake is considered extremely clean and of high quality. Due to natural filtration through rock, it requires almost no additional treatment before reaching the island’s residents. For this reason, access to the lake is strictly controlled. Swimming, fishing, or any other activities are not allowed near the water. This area is not intended for traditional tourism but is a protected natural resource on which the daily lives of thousands of people depend.
The lake can only be viewed from designated lookout points. Its preservation and isolation are among the reasons why nature functions there with almost no direct human influence. The area around the lake is rich in flora and fauna and is an important habitat for many bird species.
Drinking Water Supply
A unique story unfolds beneath the surface. In the depths of the lake, a constant and invisible balance between fresh and salt water occurs. Sea water reaches the bottom layers, while a large mass of fresh water pushes it back, preventing it from endangering the quality of the drinking water. This fragile natural dynamic allows the lake to remain drinkable.
If the water level falls, the pressure of fresh water weakens, which could allow sea water to intrude and make the lake salty. This would cause the lake to lose its primary function: providing drinking water. This delicate balance is the reason the area is under special protection.
The lake is named after the nearby village, Vrana, although residents simply call it “the lake.” This says much about its role in daily life. The name “Vransko Lake” appeared later, when it was recorded as such by the travel writer Alberto Fortis in the 18th century.



