At the junctioning of Gemer and Novohrad counties, where run into borders of settlements Šurice, Hajnáčka and Stará Bašta, there stands the Pagan Castle.
The National Nature Reserve belongs to the most valued areas. It represents a basaltic high plateau with parkland countryside, only slightly influenced by human activity and with remnants of strongly disrupted volcanic cones. At its northern edge, the lava plateau exceeds into lava flows. Ate the plateau margin, cliff structures and spectacular examples of block-type slides, represented mainly by slid rock blocks, stony avenue, crevasses and stone fields, occur. Altogether 31 basaltic caves developed here due to slope movements, with the Stĺpova (182 m) and the Labyrinth (151 m) being the longest ones. Some of them are important archaeological localities, or are valuable because of rare non-vertebrates living there thanks to cool conditions in the cavities. Basalt has thick columnar, locally slab-like jointing and its radiometric age is 4,70 } 0,31 Ma (Early Pliocene to Late Miocene). The Karad Crest west of the Pagan Castle represents the younger lava flow dated at 3,74 } 0,23 Ma. It is associated with the neck turning up more to the south. The locality is valued also for its botanical and zoological assets, such as the rare species of thermophilic flora and fauna.