Dragon Sea Cave is also a classic example of sea-erosion on the granite bedrock along the coast. The tidal waves have tirelessly hit the sea rock throughout the years, creating a natural sea gate. From this, you can see just how strong the northern winds are in Dongyin and Siyin islands. If you take a boat to tour around Dongyin and Siyin, you’ll easily find all the sea-eroded geographical landscape you learn from school: sea gates, sea stacks, sea trenches, and so on. As you travel along the northern coastline of Dongyin, you’ll find the landscape to be the best geographical classroom for everyone.

On the coast at the eastern edge of Fenghu Cape, down the path beside the gasoline station, the vicious waves blown in by violent winds have worn a long gap about 10 feet wide, along with a natural arch, in the granite bedrock. Whenever the waves get a bit high during winter, the black rocks appear and disappear in the surges like a black dragon sporting in the water. This is where the name “Dragon Sea Cave” comes from.