Hàu-Òu Introduction
A Must-Visit Natural Geology Classroom The coastal erosion landforms of Xi-yin Hou-ao are quite rich, featuring sea caves, sea arches, and sea stacks, making it one of the best places to observe such geological formations. Sea caves are formed when the protruding headlands are eroded by seawater along broken joints or softer layers of rock over time. If the erosion continues and the sea cave is eroded through, it creates a sea arch. If the top of the sea arch can no longer support itself and collapses, or if the middle section of the headland erodes away, separating the front rock from the land, this results in an isolated rock column in the sea, known as a sea stack.
