Siirasvaarat area

Strong westerly winds deposited sand from the bare beaches to shore dunes. As the strong winds continued hundreds of years, the dunes progressed in the downwind direction, where they transformed into curved parabolic dunes. The development of the dunes ceased, when vegetation bound the sand. Rokuanvaara Hill is the largest dune field in Finland, including the highest dune in the country. In addition, there are dunes in Manamansalo island and Kurikkavaara area in Vaala. Dunes are the harshest habitats in Rokua, but also habitats for many rear species.