Devín Castle Rock
Despite its relatively small area, the Devín castle site is a significant zoological, botanical, and geological locality. Its most impressive natural element is the more than 70m high rock above the confluence of the Danube and Morava rivers on which the castle is built and which is the national natural monument. Xerophytic grass/herbaceous and bushy growths on the calcareous subsoil, carbonate rock walls, and slopes with chasmophytic vegetation are protected here. The protected species Dianthus praecox subsp. lumnitzeri grows here, and the rock is also important from the geological point of view.
The bottom part of its geological foundation consists of Mesozoic marine sediments – grey dolomites and limestones. In its upper part, sharp-edge limestone/dolomite breccias (conglomerates) with conspicuous appearance are protruding.
An interesting feature is represented by 12 explored karst cracks with the character of smaller caverns. Their development can be dated back to the Badenian period some 14 million years ago. These karst areas represent the most southern Slovak caverns with the lowest height above sea level. The so-called tunnel cavern with two entrances and the length of 12m running across the rock massif is the longest one.