Polje is the largest karst landforms. Karst topography is a landscape formed from the dissolution of soluble rocks such as limestone, dolomite and gypsum. Swallow Hole is when stream of groundwater/surface water disappears in the hole. Sink hole is a depression on the limestone/dolomitic region that ranges from a shallow saucer shape to a funnel-shaped or cylindrical pipe. Uvala is defined as a complex dosed depression with several lesser depressions within its rim.