Dahua Cave Introduction
The valley landscape of the Keelung River, aside from waterfalls, features numerous smooth depressions known as "potholes" between Pingxi Station and Sandiao Ridge. The formation of potholes is due to the uneven hardness of geological rock layers, where river water carrying fine sand erodes into depressions. Subsequently, small whirlpools in these depressions continue to erode the rock, resulting in the formation of these pot-shaped cavities. Potholes typically appear in the concave bends of meandering rivers, characterized by turbulent water flow and exposed hard rock beds. Among these, the group of potholes below Dahua Station is the most concentrated and observable, where a variety of pothole types can be seen due to the interaction between water flow and rock layers, making it a natural geographical classroom.
