The mystery of the “Gigantic cauldrons”

Giant boilers can be found in several places on the territory of Finland, but today we will talk about those that are located in the town of Askola, which is about 15 km from Porvoo.
According to the scientific theory, this place is about 10 thousand years old!
Most likely, these boilers were formed during the movement of the continental glacier, when a powerful turbulent movement of water formed in its marginal zone. And this water vortex involved stones, and they, in turn, falling into cracks in the rock (granite), began to rotate quickly there, creating such holes. In some places, round stones have been preserved at the bottom of these cauldrons, which indirectly confirms this theory.

However, it is unclear how such holes could appear in this way in a very strong granite.