Karst caves

thumb|Cenote at Hubiku, Yucatan

thumb|The river Dobra (Kupa)|Dobra enters a 17 km long cave system at in [[Ogulin, Croatia.|276x276px]] A ponor is a natural opening where surface water enters into underground passages; they may be found in karst landscapes where the geology and the geomorphology is typically dominated by porous limestone rock. Ponors can drain stream or lake water continuously or can at times work as springs, similar to estavelles. Morphologically, ponors come in forms of large pits and caves, large fissures and caverns, networks of smaller cracks, and sedimentary, alluvial drains.

cave with significant vertical passages

cave formed in soluble rock such as limestone, chalk, dolomite, marble, salt beds or gypsum

thumb|Grotta Plutone is a foiba close to Basovizza, Trieste ([[Italy)]]

park in Mexico featuring cave systems and underground rivers

show caves in Toirano, Province of Savona, Liguria, Italy

cave and archaeological site in Spain

cave in People's Republic of China

cave in Castelcivita, Italy

Karst cave in Montenegro

Setergrotta (or Setergrotten) is a karst cave in Røvassdalen in Rana Municipality in Nordland county, Norway. It has a total depth of and explored length of . It is probably connected to the nearby Grønligrotta. The cave contains large galleries and sediments from the latest ice age and younger. It was created 200,000–300,000 years ago.

tunnel in the Basque Country, Spain

cave network in China

geographical region in Brazil

karst cave in Wulingyuan, Zhangjiajie, China

cave in Belgium

cave in People's Republic of China

scenic area in Yunnan, China