The Devil's Nest or Pirunpesä in Finnish, is an erosional cavity in

Kurikka Kurikka is a List of cities and towns in Finland, town and Municipalities of Finland, municipality in Finland. It is located in the Southern Ostrobothnia regions of Finland, region. The population of Kurikka is () and the municipality covers a ...

, which currently has a diameter of 14 meters and a depth of 23 meters. A staircase has been built at the bottom of the cavity and it is fenced; a small entrance fee is charged for visiting inside the fence. Access to the rest of the area is free. There is also a cafe on site.

Etymology

Pirunpesä got its name from the local population, because in the past Pirunpesä was full of large stone boulders, and in the cavities between the boulders it was thought that the

devil A devil is the mythical personification of evil as it is conceived in various cultures and religious traditions. It is seen as the objectification of a hostile and destructive force. Jeffrey Burton Russell states that the different conce ...

lived. Children have been warned that the devil might come and take them away if they got close to this gap. Some stories tell that the opening was so deep that if you dropped a small stone between the boulders, it fell from stone to stone for many minutes.

Geology

The area's bedrock consists of coarse-grained reddish

granite Granite ( ) is a coarse-grained (phanerite, phaneritic) intrusive rock, intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly coo ...

containing

feldspar Feldspar ( ; sometimes spelled felspar) is a group of rock-forming aluminium tectosilicate minerals, also containing other cations such as sodium, calcium, potassium, or barium. The most common members of the feldspar group are the ''plagiocl ...

crystals with a diameter of 2–4 centimeters. The groundmass consists of

hornblende Hornblende is a complex silicate minerals#Inosilicates, inosilicate series of minerals. It is not a recognized mineral in its own right, but the name is used as a general or field term, to refer to a dark amphibole. Hornblende minerals are common ...

biotite Biotite is a common group of phyllosilicate minerals within the mica group, with the approximate chemical formula . It is primarily a solid-solution series between the iron- endmember annite, and the magnesium-endmember phlogopite; more al ...

quartz Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The Atom, atoms are linked in a continuous framework of SiO4 silicon–oxygen Tetrahedral molecular geometry, tetrahedra, with each oxygen being shared between two tet ...

and

albite Albite is a plagioclase feldspar mineral. It is the sodium endmember of the plagioclase solid solution series. It represents a plagioclase with less than 10% anorthite content. The pure albite endmember has the formula . It is a tectosilicat ...

with

plagioclase Plagioclase ( ) is a series of Silicate minerals#Tectosilicates, tectosilicate (framework silicate) minerals within the feldspar group. Rather than referring to a particular mineral with a specific chemical composition, plagioclase is a continu ...

. To the west, northwest and north of Pirunpesä is a large deep rock area consisting mostly of

granodiorite Granodiorite ( ) is a coarse-grained (phaneritic) intrusive igneous rock similar to granite, but containing more plagioclase feldspar than orthoclase feldspar. The term banatite is sometimes used informally for various rocks ranging from gra ...

and quartz. In addition, there are

diorite Diorite ( ) is an intrusive rock, intrusive igneous rock formed by the slow cooling underground of magma (molten rock) that has a moderate content of silica and a relatively low content of alkali metals. It is Intermediate composition, inter ...

–

gabbro Gabbro ( ) is a phaneritic (coarse-grained and magnesium- and iron-rich), mafic intrusive igneous rock formed from the slow cooling magma into a holocrystalline mass deep beneath the Earth's surface. Slow-cooling, coarse-grained gabbro is ch ...

lenses in places.

Emptying the Devil's Nest

In the summer of 1980, business representative Pekka Kunnas and Jalasjärvi municipality's director of schools Kustaa Ala-Hautala were told about a special, rather round rock depression located on Ylivalli's Isovuori, which was filled with large boulders. In addition, the edges of the recess were partially rounded. It was thought that the depression might be a large-sized

pothole A pothole is a pot-shaped depression in a road surface, usually asphalt pavement, where traffic has removed broken pieces of the pavement. It is usually the result of water in the underlying soil structure and traffic passing over the affecte ...

from the time before the last

glaciation A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate be ...

. The municipality of Jalasjärvi decided to empty the depression, as Pirunpesä was a touristic and geologically interesting destination. At the beginning of 1997, the Yylivalli village committee started deepening Pirunpesä again, on the initiative of amateur scientist, writer and pseudoscientist from Turku, Keijo Parkkusen, thus reaching its current depth. The financiers of the project were the municipalit of Jalasjärvi and Spede Pasanen. The management consultant Mauno Välimäki from Yylivalli was responsible for organizing the emptying project.

References

{{reflist Caves of Finland