The reserve includes light gray limestone outcrops of Middle and Upper Devonian on which, mainly on the north side, lie Permian conglomerates. On the western edge of Żakowa Mountain, there is one of the most interesting carst caves in the region, the Hell Cave.
Area of the Żakowa Mountain reserve has an area of 50.48 hectares and was established in 1999. It covers the central part of the Zelejowskie Range located with Wsiowa Mountain (367 m AMSL) and Żakowa Mountain (363 m). The elevation is covered with beech and pine forest with many species of lime-tolerant plants characteristic of Chęciny hills. The entire protected area has traces of the old mining. It was mainly to find galena and barite. Żakowa Mountain was also a place of limestone mining, derived from this place because of the interesting colours of calcite veins coloured with copper minerals. The reserve includes light gray limestone outcrops of Middle and Upper Devonian on which, mainly on the north side, lie Permian conglomerates. On the western edge of Żakowa Mountain, there is one of the most interesting carst caves in the region, the Hell Cave. The total length of the cave is 57 metres.