Pirunlinna is approximately 1000 years old ancient castle. It has been used as posting and there are signs that the castle has been in use for a long time, near to this day. The area is stony and northern hillside is abrupt. There is wall-like construction made of rocks and there are three entries in the wall;in south, east and west. However the stonewall has lost some of its its height over time. Later the nationals began to think that the castle is built by devils and that's where it's name comes from (piru=devil, linna=castle).
On the northern side of the hill is a cave-like recess called pirunpesä (pesä=nest). It consists of erratic blocks. 90 years ago a stone-age arrowhead was found in the cave. The cave is believed to have been a shelter.
There is a path from Kulju to the mountain with signposts in the beginning of it. However it may sprawl occasionally and terrain is stony. It is possible to get pretty near to the sight by car.