What is Karst?
[[Image:SourceDeLaLoue.jpg|thumb|right|200px|A karst spring in the [[Jura mountains]] near [[Ouhans]] in eastern [[France]] at the source of the river [[Loue]]]] [[Image:WOAHdubs.jpg|thumb|right|200px|The Devil's Hole sinkhole near [[Hawthorne, Florida]], [[USA]].]] [[File:Velebit Ljubotic 3.jpg|thumb|right|200px|The karst limestone, after surface rock has weathered away, makes a ground surface which is almost imposssibly difficult for humans. Velebit in [[Croatia]].]] [[File:Tsingy de Bemaraha.jpg|thumb|right|200px| From a [[World Heritage Site]] in [[Madagascar]], the ''Tsingy de Bemaraha'' Strict Nature Reserve. Gradual erosion has produced vast fields of limestone spires known locally as tsingy, interspersed with dry forests, lakes and [[mangrove]] swamps inhabited by numerous endemic and threatened [[lemur]] and bird species.]] '''Karst''' is a [[Geology|geological]] system of rocks where water has [[erode]]d (dissolved) the [[bedrock]]. If it is very extensive, karst can be a [[geographical]] or [[Topography|topographical]] [[wikt:feature|feature]]. It is classed as a [[badland]] if it difficult to travel through the environment, which it often is. Almost always, karst is formed in [[carbonate]] rocks, such as [[limestone]] or [[dolomite]]. Since carbonate [[sedimentary rock]]s are very common, karst areas occur all over the world. Many karst regions display distinctive surface features, with [[wikt:sinkhole|sinkhole]]s being the most common. However, karst surface features may be absent where the soluble rock is ''mantled'' (covered), such as by a non-soluble rock strata on top of the carbonate strata. Some karst regions include thousands of [[cave]]s, and the water is generally [[wikt:underground|underground]]. The world's largest karst area is the [[Nullarbor Plain]], part of the area of flat, almost treeless, dry country of southern [[Australia]]. It is on the [[Great Australian Bight]] coast with the [[Great Victoria Desert]] to its north. It is the world's largest single exposure of [[limestone]]