Among the four southern islands, only Dongyupingyu was formed by Penghu volcanic lava, taking shape as basalt mesa. Basalt jointing is everywhere on the island, and there are sea trenches, sea caves, and sea erosion columns on the east and north shores. There are gravel beaches composed of coral debris on the south and west sides, but steep columnar basalt sea cliffs occupy most of the shoreline. Beside the pier on the southwest side is a mass of rock composed of breccia and geologic dikes––locals call it “the tower.”

Dongyu Pingyu is composed of two landmasses, north and south, or "front mountain" and "back mountain.” The northern landmass is the back mountain; there you can see the ruins of “vegetable houses” that once protected crops, as well as terraced fields built to conform to the terrain, a rare sight in Penghu. The village is in a low, flat valley between the front and back mountains called “Shagouzai." Houses extend from south to north near the harbor, along the leeward side of the hill. Two stone towers, Golden Dragon Pagoda and Chifu Pagoda, 
guard the island.

The looping trail around the front and back mountains will take you to Chifu Pagoda. From there, follow the shoreline trail, and you’ll come to the “front mountain,” towering at the edge of Dongyuping harbor. From that vantage point, you can take in all the island’s scenery, natural and cultural, from any angle. The nearby ocean is rich in marine ecology, abounding with coral reefs. The purple staghorn coral is stunning, a dreamlike “underwater lavender forest”––once you see it, you won’t want to leave!