Palsas are rare perennially frozen peat and mineral wetlands. They are found in the arctic permafrost region.
The permafrost is often dozens of meters thick. Palsas are formed in the thickest parts of the permafrost, where the ice begins to push a mound upwards into the peat layer. The peat insulates the preventing it from melting in the summer. Palsas can be 2,000 years old, seven meters tall, and 20 meters wide. Over time,the palsa grow breaking the layer of peat. Heat is then able to reach the center causing the palsa to collapse. A pond forms on the remains. You can see palsas in Iitto along Highway 21, 56 km north of Karesuvanto. Wooden broadwalks lead you right to them.
Iitto is located on the Käsivarrentie road, about 40 kilometres from Kilpisjärvi. There is a rest area on the river’s side of the road, where you can park your car. Walk along the board walk for about 100 metres, there are signs.