The waves clash against the cliffs day after day. As time passes, the cliffs begin to erode and become flat rock surfaces that are almost of the same elevation as sea level. Such a geological structure is known as a wave-cut platform.
The wave-cut platform near Dali of Toucheng is particularly wide. It runs approximately parallel to the regional stratum, which happens to run in the same direction as the northeasterly monsoon winds. As a result, erosion caused by the waves is not as severe as it is along the coastline between Bitou Cape and San Diego Cape in Keelung. Crisscrossing patterns can often be seen on the sloping geological structures.
