This area, which is well suited for wilderness trekking, mostly consists of highland in about the altitude of 200 - 300 metres. It is treeless or grows thin fell birch forest. Especially for fishermen this wilderness area is a dream destination: there lives abundance of fish in the many rivers, brooks and lakes of the large area. Rivers Vetsijoki and Pulmankijoki are the two remarkable tributary rivers of the River Tenojoki, which dominate the middle and the northern parts of the wilderness, flowing in their deep carved valleys on the lower course. The River Näätämöjoki, flowing in the southern part of the area, is popular with fishermen: Where it begins at the Lake Iijärvi, it is quite small but has many rapids. After the tributaries join it, it becomes more than 100 metres wide, calmly flowing stream. The waters of the wilderness area flow into the freezing cold Arctic Sea.
The mires and the numerous lakes, which are found especially in the southern part of the area, have a rich set of bird species. Waters and mires often seem to be organised in lines from southwest to northeast, in parallel with ridges and esker formations. In the southern part of the area, it is not easy to orientate oneself: the fell birch forest is confusingly dense and the sandy hills between the mires are low. The gentle fellslopes, highland heaths and esker formations make the terrain quite easy for a hiker.
Fells and Hills
There are two actual fell areas in Kaldoaivi Wilderness Area: Guorboaivi-Gálddoaivi Fells in the middle of the area, and the fells south of the River Tenojoki, which reach for the sky in the northwestern part of the wilderness area. The shape of the landscape in the treeless fell areas is very gentle and quite low. Only a few fells rise over 400 metres. At many places on the fell slopes you can see skeletons of fell birches without their leaf crowns, which reminds us of the mass occurrence of the caterpillar of the Autumnal Moth (Epirrita autumnata) in the mid 1960s. Tšuomasvarri Fell (Čuomasvárri) (435 m), is seen in the northeastern part of the area, near the Norwegian border. It is geologically different from the rest of the rock foundation in the area: it consists of ultrabasic rock.
The Soil and the Bedrock
After the latest Ice Age, the Arctic Sea stretched to the valleys of the Rivers Näätämöjoki and Pulmankijoki. The Lake Pulmankijärvi also is an ancient fjord of the Arctic Sea. Kaldoaivi Wilderness Area, located on the head of the "Maiden of Finland" in the map, is geologically diverse. There are plenty of different formations created after the Ice Age, such as drumlins, border moraines and eskers. The bedrock is more alkaline in the wilderness area than elsewhere in the Inari Lapland. Especially this can be seen in the lush herb-rich forests in the valleys of the brooks in the area.