Fells are mountaineous ecosystems. They can be defined as old, flattened orogenic mountains the peaks of which reach elevations where tree growth is not possible.

In Finland, there are no snow-capped mountain ranges like the Central European Alps, but there are a lot of fells. They can be found specifically in Northern Lapland.

The harsh conditions of these fells make them unique ecosystems. Although the number of plant and animal species is lower in fells than in forests and other more temperate ecosystems, many species can only be encountered in fell regions.

Most of the surface area of Finnish Lapland consists of coniferous forest, but in higher elevations some species common to the tundra can be found.