Introduction to sea-eroded potholes: There are originally some caves of different depths on the surface of coastal rocks due to differential weathering. When seawater carries stone particles into the caves, the stone particles are driven by the rotation of the seawater and interact with the interior of the caves. Friction occurs, and drilling continues downward and around. As weathering proceeds, the cavity gradually expands and deepens, becoming a sea-eroded pothole like a deep well. Therefore, stone particles usually appear in sea-eroded potholes. .