The municipality of Salla is a geologically significant area:
It includes nine Nationally Valuable Rocky Areas, two Nationally Valuable Moraine Formations (Kallunki and Saija) and four Nationally Valuable Aeolian and Littoral Deposits. The remnants of the Ice Age found in Salla include a glacial lake shore and giant’s kettles.
The Kallunki hummocky moraine area located to the south of Salla extends southeast from Kursu as a narrow zone that continues beyond the Russian border. The highly dispersed hummocky moraine area is approximately 60 kilometres long and 15 kilometres wide. The Saija hummocky moraine area is located southeast of Savukoski. The wedge-shaped field grows wider towards Saija and the national border. It is 50 kilometres long and 20 kilometres wide. Moraine formations are Finland’s most diverse group of geomorphological formations. They include formations of very different origins, structures and shapes. Moraine formations include geological, biological and scenic diversity that has considerable significance with regard to nature conservation value. Moraine formations involve similar scenic and organic values as rocks and eskers; high ridges, partly open vegetation types, shaded inclines and nutrient-rich soil with groves and fens. Moraine formations therefore have general significance related to economic activity, nature and landscape protection, as well as outdoor recreation. Moraine formations also often have cultural significance in terms of Finland’s settlement history and the history of economic activity.