Potholes

kettle holes, natural kettle-like depressions formed in hard rock by the rotating motion of water that is carrying rock. Potholes are created in river channels in stretches with rapids and waterfalls, at the bottoms of glacial valleys by glacial meltwater that has been hurled through cracks in the ice to the bedrock of the glacier bed, and on seashores by the surf. Potholes reach several meters in diameter and as much as 20–30m in depth.