Lake Vrana (Croatian: Vransko jezero), in the centre of Cres island, is a fresh water lake, 1.5 km wide and about 7 km long. The town of Cres has been supplied with drinking water from the lake since 1953, and the towns of Mali and Veli Lošinj received their supplies ten years later. It was thought at one time that the water in the lake was linked to some mainland source by underground streams, but it has since been established that in fact it originates from the atmosphere.
The lake is one of cryptodepression characteristics. It was formed by very heavy tectonic movements along a longitudinal relaxation fault which now contains 220 million m3 of fresh water. Comprising an area of 5.8 square kilometres (2.2 sq mi), the depression reaches a depth of around 60 m below the sea level, but its surface lies about 14 m above it, oscillating by about half a metre, meaning the maximum depth is 74 metres (243 ft). It's surrounded by mountains like the 483 m high Mont Elmo and Mount Perskra of 429 m.
The lake contains pike, tench and carp. There are also eels, but their origin is still unclear.
The village of Vrana, above the lake, is located 15 kilometres (9.3 mi) south of the town of Cres.