Ans: The depression of the ground surface that takes a shape of a funnel, and is made by a solution of limestone. The most common landform in the Karst region is doline. They are described as medium-range doline with medium diameter. Enhanced dissolution through the focusing on drainage, by a collapse underneath a cavity, down washing of weekly sedimented soil is the mechanism followed by doline. In most pseudokarst terrain doline or sinkholes are formed. Naturally formed arches and curves are created by a non-karstic mechanism. Closed depression with characteristics of evaporite and carbonate karst landscape is also known as dolines or sinkholes.