The natural monument is a cave 1,700 m long with an area of 14,000 m², formed by the Bgheristskali River in thin- and medium-bedded limestones of Lower Cretaceous age. The river first forms a closed valley and then sinks into a narrow ponor. The cave begins with an opening 30 m long and 40–50 cm high, choked with fine sand and branches washed down from the surface, into which the streams of the Bgheristskali flow. Here it is joined from the right by permanent streams entering from the Melouri and Didghele caves. The river crosses the whole cave latitudinally and is lost at the western end in rockfall and a shallow siphon. The Bgheri cave clearly shows the traces of the streams' erosional work.