Hou'ao Introduction
An Essential Natural Geology Classroom The coastal erosion landforms at Xi Yin Hou Ao are quite rich, featuring sea caves, sea arches, and sea stacks, making it one of the best places to observe coastal erosion formations. Sea caves are formed when the protruding headland in the sea is gradually eroded by seawater along fractured joints or softer layers in the rock, leading to the hollowing out of the cliff. If the erosion continues and the sea cave is eroded all the way through, it forms a sea arch; if the top of the sea arch cannot support itself and collapses, or if the middle section of the headland is eroded and collapses, separating the rock mass at the front from the land, it creates a sea stack isolated in the ocean.
