Karst landforms are seen concealed under the surface of the earth.

Karst landforms are seen concealed under the surface of the earth because-

1. Warmer humid climate has greater amount of vegetation, which supplies CO to sub-surface water. 

2. CO is necessary for the acidity of water which makes dissolving easier. 

3. Water saturated with dissolved CO should have easy movement. 

4. The greater the permeability of the rock, the faster ground water will flow. 

5. The fractures and joints in the rocks allow passage of water. 

6. In the areas of water-soluble rocks, such as limestone and gypsum the acidic water dissolves the rock and various landform develop underground. 

7. Thus, landforms developed by underground water anywhere in the world are called karst landforms.