Siaomen Natural Monument. Siaomen Island is surrounded by the sea, and has long been shaped by waves and tides, creating diverse coastal erosion landforms. Siaomen Island is surrounded by the sea, and has long been shaped by waves and tides, creating diverse coastal erosion landforms. Among them, "Whale Cave" is an easily accessible and observable sea-eroded arch in Penghu. It was formed by the erosion of waves, which pierced through the sea cliff, creating a hollow space, hence its name as a sea-eroded arch. If you walk into the cave, you can also hear the powerful sound of the sea. Siaomen Island is surrounded by the sea, and has long been shaped by waves and tides, creating diverse coastal erosion landforms. Among them, "Whale Cave" is an easily accessible and observable sea-eroded arch in Penghu. It was formed by the erosion of waves, which pierced through the sea cliff, creating a hollow space, hence its name as a sea-eroded arch. If you walk into the cave, you can also hear the powerful sound of the sea. Additionally, on the rock walls beside the island-circling trail, clearly exposed and complete rock layers are visible. From top to bottom, they are silicic basalt columnar joints, peat layers, siltstone layers, and sulfur layers. This is the "Crater Lake Remnant." Like Whale Cave, it possesses rarity and uniqueness, serving as the best field material for understanding the process of coastal erosion and geological evolution. Therefore, it was simultaneously announced as the Siaomen Natural Monument. Also famous in the Siaomen area is the "Siaomen Formation," which, according to geological age analysis, can be divided into upper and lower layers. The upper layer is shell limestone, cemented by fossil shells, quartz grains, and tiny foraminifera.
Address: 澎湖縣西嶼鄉11-12號
Hours: 00:00–23:59
Penghu