There are a total of eight karst areas in the Little Carpathians: the Devín Carpathians, Borinka (Pajštún), Cajlan, Kuchyňa-orešany, Plavecký, Smolenice, Dobrovodský, and Čachtice karsts. The most important karst forms include caves Deravá, Tmavá skala, Driny, and Čachtická, and caves along the Borinský potok. Driny, a limestone cave, is the only cave open to public. Major streams include Vydrica and Suchý jarok.