Lance waterfall - The giant's cauldron

When it falls, the water goes deep below the smooth surface of the plunge pool. At the bottom, the river bed takes the impact of the falling water’s constant force. A kind of giant cauldron is created, with is base becoming smoother and smoother, deeper and deeper with the water swirling around more and more. It is where the huge boulders carried along by the mountain stream fall, and their abrasive qualities also play a role before they continue towards the mouth of the river.