Looking at Dongyin from the sea

Dongyin Island is located on the northeastern side of the Matsu Islands. Its rocks are primarily composed of diorite, which has a grayish-green color. Granite and diorite are both igneous rocks, characterized by their hardness. They were formed approximately 85 to 100 million years ago.

The sea tour of Dongyin departs from Zhongzhu Port. On the sea cliffs, you can see many military relics from the period of martial administration, such as gun emplacements or military outposts. Passing by Shuangzi Reef’s Matsu islands Tern Refuge, you can observe the ecology of black-tailed gulls. Additionally, Dongyin's Lienu Yikeng (Chaste Maiden's Righteous Pit), Yixiantian (One-line Sky), and Yanxiu Chaoyin are all very typical sea trenches. The towering sea cliffs, over 100 meters in height, are even more impressive and awe-inspiring when viewed from the sea. The rocks have been shaped by coastal erosion into forms resembling squirrels and chameleons, which can only be appreciated from the sea.

Dongyin Island has significant topographical variations. It is mostly surrounded by sea cliffs, which rise rapidly from sea level to Mount En'ai at an elevation of 173 meters, emphasizing the steep terrain. The well-developed joints in the diorite are the main reason for the steep coastal cliffs. The rich fishing resources near Dongyin Island make it an excellent spot for rock fishing. People can often be seen fishing at the base of the sea cliffs and on the reefs.