Geological site, monument to volcanic activity. In the former quarry, you can see layers of tuffites (hot rock fragments that were ejected during the eruption of the Velký Roudný volcano, fell into the water and solidified), and sediments of non-volcanic origin.
The stone in the quarry was probably quarried already in the Middle Ages, judging by its use on historic buildings in the vicinity.
The volcanic subsoil is suitable for heat-loving plant species, so you can find here in large numbers, for example, the barberry or the cardouzek star