The Emblem of Friendship Nature Reserve Sights of Lentua

The Lentua Nature Reserve is part of the Friendship Park, which consists of five separate nature reserves. The Friendship Park is the Finnish part of the Finno-Russian Friendship Nature Reserve. The emblem of the Friendship Nature Reserve features two wild forest reindeer, reflecting the friendship between the two countries and their cooperation for the benefit of nature conservation. One of the fundamental goals of the Friendship Nature Reserve is to protect the wild forest reindeer (Rangifer tarandus fennicus) and its habitats, which makes this animal a natural choice for the emblem.

Read more about wild forest reindeer ( and about securing its breed purity in the Ministry of Agriculture and Forestry's website ( The wild forest reindeer has also its own web-site in Finnish, English and Russian in

WildForestReindeerLIFE is a seven-year (2016–2023) population management and conservation project, with the central aim of reintroducing wild forest reindeer (Rangifer tarandus fennicus) to their native habitat in southern Suomenselkä, Finland. In addition to the reintroductions, the project will implement a diverse range of measures that promote the strengthening and dispersal of the wild forest reindeer population and monitor population development. Read more about the WildForestReindeerLIFE project.

The landscape of Lentua is also characterised by clean beaches. Photo: Eero Korva

The Lentua Nature Reserve includes the islands and shore areas of Lake Lentua, which is a rather large lake for Kainuu. The core of the area is formed by the open part of the lake, which is surrounded by mazelike bays and points with various shorelines. There is an abundance of islands, and all round the lake you can see wooded hills and slope areas. The landscape is also characterised by esker formations, clean beaches and stark but beautiful rocky shores.

The central parts of Lentua are peaceful and wilderness-like. The shores in the reserve are in their natural state, but most of the privately owned shore areas contain holiday cottages.

The islands are austere. The largest islands, among them Salonsaari and Vitikkosaari, are rocky. Multisaari and Kotasaari are part of a vaster esker formation. There are maintained resting places for hikers on some of the islands. Lentua is a very popular recreational area.

Wide Lake Lentua

Lentua is the largest unregulated lake in the basin of the Oulujoki River. Its surface is 168 m above sea level, and the annual water-level fluctuation is about 1 m. The average depth of the lake is 7.6 m, but there is a 52-metre-deep depression at the front of Timoniemi Point, which is the deepest point in the lakes of Kainuu.

Lentua's waters can be said to be in a near-natural state. The watercourses flowing into the lake are humic, but humus sinks to the bottom in a wide basin, making the water clearer than in other water bodies in the Oulujoki River basin. The water quality is good, though diffuse pollution from agriculture and forestry as well as fish farming make Lentua slightly eutrophic.

Lentuankoski Rapids

Lentua's waters drain into Lake Lammasjärvi via the magnificent Lentuankoski Rapids, which are the largest rapids in Kuhmo. They were previously an important route for travel and log floating, and are nowadays one of the most well-known natural attractions in Kuhmo. Actually, the rapids are not included in the Lentua Nature Reserve, but they are covered by the Shore Conservation Programme. A Finnish bank, OKO Group, has established a private nature reserve on the west bank of the rapids.

The Lentuankoski Rapids are not part of the Friendship Park, but its banks are protected under the Shore Conservation Programme. The west bank belongs to a private nature reserve established by a Finnish bank, OKO Group. The rapids and the waters are protected under the Act on the Protection of Rapids.

Lentuankoski consists of the Iso Lentuankoski (Large Lentuankoski) and Pieni Lentuankoski (Small Lentuankoski) Rapids, which are separated by a short body of still water. The Iso Lentuankoski Rapids flow wildly for about 300 metres and drops about 3,3 metres. The Pieni Lentuankoski Rapids flow more calmly towards Lake Lammasjärvi, but are slightly longer, about 400 metres. The rapids have a total drop of 5.3 metres, and rafting is rather demanding, particularly in the upper rapids.

Lentuankoski Rapids. Photo: Kia Olin

Rocky Shores and Sandy Beaches

Lentua's shores are mostly rock-strewn moraine shores that are craggy in places. Cliffs and smooth stretches of bedrock are also a common sight. The sparse vegetation is susceptible to erosion due to the thin layer of humus. The fine sand of the eskers is easily carried away by wind and water, and has thus piled up to form beaches. There are very few boggy shores in Lentua, since there are not that many mires either. Post-glacial land uplift can be seen in the gradual tilt of the lake basin towards the east. Land has been left dry in the western part, and the eastern shores have become waterlogged.

Cliffs are a common sight in Lentua. © Risto Sauso

Hum of the Forest

The forests of Lentua belong to the middle-boreal forest zone. The most common forest types are the dry Empetrum-Vaccinium (crowberry-bilberry) and the mesic Vaccinium-Myrtillus (bilberry-lingonberry) types. Drier Calluna (heather) and Cladina (lichen) type forests can be found in small areas on cliffs and esker slopes. There are very few herb-rich forests in the area. Their vegetation types are related to river bank vegetation or have been introduced by humans. A forest type of its own in the Lentua area is a kind of ‘humanised forest', which includes meadows, fields and pastures that are becoming forested.

The forests were first affected by slashing and burning as well as tar burning and later by large-scale cuttings and forest regeneration. The forests are managed pine forests growing on rather dry soils. Individual old trees can be seen on shores and cliffs. During the last decades, forest management has not been practised much, and there has been progress in the return of the area to its natural state. An example of this are the rather young forests formed by pines and deciduous trees on most of the islands.

Very Few Mires

There are very few mires in the Lentua area, and most of them have been drained. Large mire areas have been taken into agricultural use. The mires have been poor and acidic Sphagnum mires. The dominant mire site types have been dwarf-shrub pine bogs, Empetrum-Sphagnum fuscum bogs, spruce-pine mires and herb-grass spruce mires. There have not been many flark fens, rich fens or swamps in the area. Small pristine mires can be found on the area's islands.

Fish-rich Waters

Lentua is a valuable lake in terms of its fish population. In recent decades, this population has been managed actively and has been affected by professional fishing. The most important commercial fish in Lentua is the vendace (Coregonus albula). Its annual catch is 10 to 50 tonnes. The natural state of the lake is reflected by the brown trout, grayling and whitefish populations (Salmo trutta m. lacustris, Thymallus thymallus, Coregonus lavaretus). Examples of other species of fish found in the waters of Lentua are the northern pike (Esox lucius), burbot (Lota lota), perch (Perca fluviatilis), roach (Rutilus rutilus) and Eurasian minnow (Phoxinus phoxinus).

Numerous Birds

On the islands, you can mainly see birds of managed forests and shores, such as tree pipits (Anthus trivialis), common sandpipers (Actitis hypoleucos), white wagtails (Motacilla alba), willow tits (Parus montanus), common redstarts (Phoenicurus phoenicurus), as well as black grouse (Tetrao tetrix), capercaillies (Tetrao urogallus), hazel grouse (Bonasa bonasia) and willow grouse (Lagopus lagopus). Typical waterfowl include the goldeneye (Bucephala clangula), red-breasted merganser (Mergus serrator) and goosander (Mergus merganser) as well as black-throated diver (Gavia arctica). The whooper swan (Cygnus cygnus) is also a common sight. The open waters are a feeding place for dozens of red-throated divers (Gavia stellata) nesting near Lentua. Other nesters in Lentua include the common tern (Sterna hirundo), common (Larus canus) and black-headed gull (Larus ridibundus) as well as the lesser black-backed gull (Larus fuscus), which is becoming increasingly rare. The osprey (Pandion haliaetus) comes to the lake to prey. In winter you can see white-throated dippers (Cinclus cinclus) diving in the ice-cold water of the rapids.

Nesters in Lentua include also the common tern (Sterna hirundo), common (Larus canus) and black-headed gull (Larus ridibundus) as well as the lesser black-backed gull (Larus fuscus), which is becoming increasingly rare. © Risto Sauso

Other Inhabitants of Lentua

You can encounter wild forest reindeer (Rangifer tarandus fennicus) in Lentua in both summer and winter, since the area is important for them for living and migration. Wild forest reindeer may be followed by grey wolves (Canis lupus), wolverines (Gulo gulo) and lynxes (Lynx lynx). Other animals in movement in the area include elks (Alces alces) and red foxes (Vulpes vulpes) as well as mountain hares (Lepus timidus), red squirrels (Sciurus vulgaris) and pine martens (Martes martes).

You can encounter wild forest reindeer (Rangifer tarandus fennicus) in Lentua in both summer and winter. Photo: Eero Korva

Modest Beauty of Plants

Lentua's vegetation is closest to the nutrient-poor Equisetum-Phragmites (horsetail-reed) lake type. A typical plant growing on the shores of the lake is the sedge Carex omskiana. Also common are the woollyfruit and beaked sedge (Carex lasiocarpa, Carex rostrata) as well as the creeping spearwort (Ranunculus reptans), which is a pleasant little shoreline species not noticed by many people. The species of clean and clear waters are represented in Lentua by quillworts (Isoetes) and the water lobelia (Lobelia dortmanna), which flowers in shallow waters in July, as well as the pond water-crowfoot (Ranunculus peltatus), which floats on the water and produces pretty flowers in midsummer. There is also the rather rare shoreweed (Littorella uniflora) growing in the lake and the common butterwort (Pinguicula vulgaris) growing on the shores.

Right by the water's edge, you can find the blue-flowered corn mint (Mentha arvensis), common skullcap (Scutellaria galericulata) and dark red marsh cinquefoil (Potentilla palustris). The shoots of the common spike-rush (Eleocharis palustris) emerge from the shallow shore water.

The purple moor-grass (Molinia caerulea), stone bramble (Rubus saxatilis), lily of the valley (Convallaria), heath spotted orchid (Dactylorhiza maculata) and cinnamon rose (Rosa majalis) can be found on the islands and peninsulas in particular. The area is also home to the twinflower (Linnaea borealis), leather leaf (Chamaedaphne calyculata) and heather (Calluna vulgaris), the provincial flower of Kainuu. However, the speciality of the area is, without a doubt, the cross-leaved heath (Erica tetralix).

Sights of Lentua

Lentuankoski Rapids and Lake Lentua

The Lentuankoski Rapids and Lake Lentua are the best-known and most popular natural attractions in Kuhmo. Nature in Lentua is a memorable experience at various times of the day and year. There is also a footbridge suitable for the disabled by the rapids.

River rafting. Photo: Eeva Pulkkinen