Houtong Potholes

The potholes of the Keelung River are a world-class geological landscape. These geological features are typically more common in the upper reaches of rivers. Potholes are formed by the drilling and eroding action of strong eddies carrying sand and gravel on the riverbed. As water swirls them, circular holes are gradually formed over time, hence the name 'potholes'. Between Houtong Station and Sandiaoling Station on the Pingxi Railway Line in Ruifang District, the Keelung Riverbed cuts into a hard layer of Nuannuan sandstone. The rock surface there features numerous smooth, circular depressions, which are geomorphologically known as potholes, thus forming the unique Keelung River Pothole landscape.