In addition to the stone spheres in Megoňky and Klokočov,Kysuce features another European geological rarity – a naturally surfaced light crude spring with occasional discharge of self-igniting methane can be found on the east edge of the region and the nearby settlement of Muchovec in village Korňa.
The crude contains a high percentage of oils and comes from oil-bearing flysch layers. The crude is of a very high quality, however drill holes which have been made in the surroundings since the end of the 19th century show that there is not enough crude to start industrial production. Parafin based crude of high quality with low sulphur content, similar to Brent crude had been produced for several years in the past. Nearby the spring a drill hole was made in the cadastral territory of Korňa in 1997-1999. The planned depth was 1,500 metres, however the drill hole is less than 1,300 metres. In spite of the fact that crude was not discovered, the whole area remains perspective. In 1973, the crude spring was declared a protected natural location, in 1995 it has been reclassified to a nature monument with area of 0.171 ha.
