Lake Ähijärv, with a meandering shoreline that measures some 3 kilometres, is a typical eutrophic lake. There are a number of campfire sites and swimming spots on its shores. Its average depth is 3.8 m, with a maximum depth of 5.5 m. The biota of Ähijärv is very diverse, and more than a hundred algae species have been recorded here. It is known as a good fishing spot – in addition to other freshwater fish, eels and pike perches inhabit the lake. Once, crayfish were also abundant in the lake.