cliff

The steep, vertical edge of a mountain, hill, or mesa. Cliffs expose the rock types and different earth sediments of the mountain, and can be created either by erosional forces or by structural forces. Erosional cliffs are created when the rock is weathered down starting at their base. Erosional cliffs are prevalent in areas with mountainous sandstone or sedimentary rocks that are prone to weathering. Structural cliffs are created with fault displacement or when a significant landslide occurs. In most cases, there is a sudden large drop past the edge of the cliff, creating a dramatic change in elevation between the top of the geological formation and the bottom of the cliff.