The Kraków-Częstochowa Upland is built of limestone. A peculiarity of the highlands are numerous inselbergs, standing alone on an even surface and rock debris, looking like castle ruins. All this creates an extraordinary landscape. The Ojców National Park is the most attractive part of the highlands. Niecka Nidziańska (300 m) it is partially covered with loess in the south-western part. In the vicinity of Wiślica and Busko, there are the largest deposits of gypsum in Poland.