Prokoško lake is located on Vranica mountain between Debelog brda (1858 m), Glavičice (1691 m), Trbevića i Ćosa (1864 m). The lake is located at 1635 m above mean sea level. It's 426 m long and 191,3 m wide.

The surface area is 48.000 m2 and the lakes maximal depth is 13 m.

The formation of the Prokoško lake was strongly influenced by fluvial, gravitational and other processes. Glacial processes didn't have a big impact on the morphology of the terrain as the circumstances weren't ideal for forming glaciers.

Prokoško lake is a nature monument by law as of 2005, including it's protected surroundings.

It was declared a nature monument because of the big number of endemic species of animals and plants and also because of the water richness of the surrounding area.

There exists a endemic subspecies of the Tritius alpestris reiseri in Prokoško lake. It differs from the typical species with its proportinaly bigger head.

It was dicsovered in 1891. by Othmur Reiser and described in 1902. by Werner.

It reaches a maximal length of 12 cm and lives in shallow waters and on the lake banks. It feeds on insects and snails that it finds in the water.

Lately, unfortunately the Lake is loosing its original beauty due to illegal buildings, houses and sewage system, what really harms the lake.