Lake Paanajärvi lies in a deep canyon, which appeared over 1,5 billion years ago as a result of earthquakes. Later, glaciers rounded the summits of the surrounding mountains. Paanajärvi is one of the deepest lakes in Fennoscandia (128 m). The summit of Mt. Mantutunturi located nearby towers above the bottom of the Lake by 542 m.
The very geological structure of the territory is of extreme interest because of the abundance of rare minerals. Marbles and other volcanic rocks, and favourable microclimate promote an abundance of vegetation. So, in the spruce-dominant groves growing on the southern slopes you can encounter such wonderful Orchids as Lady's-slipper, Fairly slipper and Red baneberry. The slopes of Mount Niskavaara and Mount Munavaara have magnificent forest areas where Diplazium sibiricum grow, and on the Ruskeakallio rocks (60 m high) you can find Baby's breath and Wall-rue spleenwort.
Three fells with open summits dominate in the Park. Of them, Mt. Nuorunen (576 m) is the highest, and Mt. Kivakkatunturi (499 m) makes a scenic background to the Kivakka Waterfall, one of the main sights of the Park.
Open peaks of Mt. Kivakkatunturi offer beautiful panoramic views. To the north the River Olanga with the raging Kivakkakoski Waterfall can be seen. The River snakes through forests and meadows near the abandoned Vartiolampi settlement, expanses of Lake Pyaozero show blue in the south and east. Mt. Nuorunen opens a view upon the rugged Lake Tavajärvi in the south-west, the Kuusamo fells with the Rukatunturi skiing centre rise in the west, from the other side of the border.
In September the slopes are very scenic. The open summits are stained dark-red by Alpine bearberry, and the slopes are coloured gaily by birch and aspen trees. In winter, snow caps on the trees at the edge of the forest create quaint figures.

Unique fauna
Most of the forest in the Park is completely untouched. Near the Lake and along the River Olanga the foundations of houses are preserved, and in the forest there are signs of selective cutting. The masters of these forests are the Brown Bear (Ursus arctos), Wild Reindeer (Rangifer tarandus fennicus), and Wolverine (Gulo gulo). Altogether, 36 mammal species inhabit this area: elks, lynxes, hares, lemmings, and others. These shy creatures are rarely seen by man but their tracks are often found. In wintertime, near the rivers Otter (Lutra lutra) can be found, as well as the Wolf (Canis lupus) tracks.
Many rare bird species nest in the Paanajärvi National Park. Golden eagle can be seen hovering over its domains. Black-throated diver finds refuge on the large lakes, and Red-throated diver nests on small marshy lakes. Their voices fill the summer nights with mystery. Red-flanked bluetail, common for eastern taiga, sings in dense spruce forests, and Little bunting on the fringes of pine mires. Travellers can come across the great grey owl, which protects its nest fearlessly. On the open summits you can meet local courageous inhabitants: Lemming and Ptarmigan.
The Grayling population is high in the Park's rivers. In summer, Brown trout swim up the Olanga River from feeding in Lake Pyaozero to Lake Paanajärvi and further on, across the border, up the Rivers Kuusinka, Oulanka and other small rivers to the upper parts, to habitual spawning sites. The heaviest brown trout specimens caught weighed between 10 and 12 kg. Char inhabit some lakes in the Park. Lake Paanajärvi is inhabited by relic crayfish left from the time when after glacier's retreat it was a bay of the White Sea.