The natural monument is formed in Lower Cretaceous limestone; the shaft opens as a wide fissure on a slope covered with deciduous forest. The fissure, running north, reaches 60 m in length and 2–25 m in width. At its bottom, 25 m below the surface, lies a siphon lake 45 m deep. The fissure siphon is part of a cave system, and the level of the siphon lake coincides with the level of the outlets of the Kumi River.