The islands of Vaajasalo and Mäntysalo make up most part of the area of the National Park. In addition, there are small islands and rocky islets, and a few areas on the mainland. The narrow bays and straits surrounded by sheer cliffs form a labyrinth inside the main islands. The continental ice sheet carved the deep lakes and the high rocks. At its deepest there is 47 metres of water in Kolovesi. The surrounding water areas and shores are included in the National Shore Conservation Programme.
The shores of the park are rugged rocky shores. So called Devil's fields consist of boulders and rocks, and were formed after the Ice Age by the great changes in the sea level. The individual profiles and crushed forms of the rocks are unique to Kolovesi. The forms of the shores vary from rocks with pine trees to heaps of angular boulders and sheer cliffs.
The Eurasian Eagle Owl (Bubo bubo) and the Common Raven (Corvus corax) nest on the cliffs. The Red Fox (Vulpes vulpes) and the Eurasian Badger (Meles meles) can be seen between the boulders, and sometimes in the winter even the footprints of the Lynx (Lynx lynx) are found on the snow. Fishing in the clear water live the Saimaa Ringed Seal (www.metsa.fi, in Finnish) (Phoca hispida saimensis) and the Otter (Lutra lutra), which is also quite rare.
The Rare Inhabitants of the Old-growth Forests
On the islands, behind the shoreline cliffs with stubborn pine trees, there are overcast, quite luxuriant depressions with mixed-wood forests dominated by spruce but also growing Birch (Betula), Aspen (Populus tremula) and Pine (Pinus sylvestris). In damp places there are spruce bogs, and in some places under the cliffs even small herb-rich forests. In the corner of some bays there are flood meadows dominated by sedges (Cyperaceae), which have been mowed in the old times.
The old forests of the park are a habitat for many species of old-growth forests, which have become rare, such as hole nesters, beetles living on deadwood, and shelf fungus (Polyporaceae). In the old mixed-wood forests live also the Greenish Warbler (Phylloscopus trochiloides) and the Wood Warbler (Phylloscopus sibilatrix). Of the threatened species, the Black-throated Diver (Gavia arctica), the Red-throated Diver (Gavia stellata), the Osprey (Pandion haliaetus), the Lesser Black-backed Gull (Larus fuscus), the Northern Hobby (Falco subbuteo) and the Red-breasted Flycatcher (Ficedula parva) have been seen in the park.
The abundance of rare species shows the value of the old-growth forests. Therefore Kolovesi is an important conservation area for the forest ecosystems of Southern Finland. More than half of the National Park´s forests are over a hundred years old. Even more interestingly, succession of forests of different ages can be found in the park. The forest ecosystems are complemented by former commercial forests, which are young, dense and dominated by deciduous trees. There you can hear the exotic whistle of the Golden Oriole (Oriolus oriolus), a bird with yellow and black colours, which sounds like a flute.