The Lanajoki conservation area was established in the 1980s on land owned by Antti Pätilä, the former mayor of Ruokolahti. In Lanajoki conservation area you can observe the different stages of forest development in their natural state. The park includes old, large black alders (Alnus glutinosa), the Lanakoski waterfall, fine flower meadows among other things. The Lanajoki river, which flows into Lake Saimaa, enters Lana Park from Lake Vasari via Lakes Syväjärvi and Särkijärvi. In summer the river is not very watery, but in spring you can see a beautiful rapids in Lanapuisto. Remains of the old mill are still visible. In and around the conservation area, there are dozens of spruces, some pines and birches. The largest trees have a girth of over three metres. The conservation area and the associated black alder grove have long been a popular outdoor destination, but the area has been known only to a small number of people, as there are no guides to the area.
A fish path for endangered migratory fish was restored in the conservation area in 2019. Thanks to the path, trout and other aquatic organisms will once again be able to freely ascend to the Lanajoki river and the lakes and streams above it. For a long time, fish had not been able to rise from the Saimaa to Lanajoki because the river's natural channels had dried up as a result of excavation. Fish passage was blocked cause of a natural ledge in the river, but a fish path around the barrier allows fish to pass again. A very small but important restoration project which has opened up 10 kilometres of upstream from Saimaa to the upper lakes of the Lanajoki. The area's bridges were repaired by the municipality of Ruokolahti in 2022, when a lookout was also built.