There are huge erratic blocks on the edge of the Peurasuo in Rimmilä. Boulders form caves of various and different sizes. The site is accessible by a forest road and forest trails. The name of the Stålberg stones has come after the man who was hiding on them. Boulds of stone are located on the edge of a bog, Peurasuo has been preserved as an exceptional natural condition and is a member of a nationwide swamp protection program.