Xiaomen Natural Monument

Xiaomen Islet is surrounded by the sea. The long-term action of waves and tides has sculpted a variety of diverse marine erosion landforms. Among these, "Whale Cave" is an easily accessible and observable sea arch in Penghu. It formed because ocean waves eroded and penetrated the sea cliff, making it hollow, which is why it's called a sea arch. If you walk inside the cave, you can also hear the truly powerful sound of the ocean waves.