Dongyin Township, located at the Northeastern end of the Matsu Islands, is the northernmost territory of the Taiwan region, about 100 nautical miles northwest of Keelung on the main island of Taiwan. Comprised mainly of the two major islands of Dongyin and Xiyin, it has a total land area of 4.4 square kilometers. The entire township is atop precipitous cliffs, and is the only one of the Matsu Islands without a beach. It boasts beautiful scenery formed by ocean erosion, abundant fish and shellfish, numerous species of flora and fauna, and is the southernmost recorded mating ground of the black-tailed gull. The two islands of Dongyin and Xiyin are connected by an embankment constructed by the Armed Forces of the ROC, and the islands have a large number of military outposts. Dongyin's important military role of protecting the northern frontier of the Matsu Islands gives it a strong battlefield character that remains to this day.
Dongyin was formerly known as Dongyong, literally "Eastern surge," for the deep, turbulent waters that surround it; the name was changed to Dongyin in 1956, and a township formally established. According to local legend, the small island was thrust up from the sea off the northwestern coast of Fujian, explaining where the original name Dongyong came from. But the actual origin of this name should be credited to sailors. Because the waters around Dongyin are the deepest among the Matsu Islands, as ships sailed East from Nangan towards Dongyan, they encountered larger waves after passing Liang Island. Hence, “eastern surge.”
Dongyin’s deep waters and flowing tides encircled by reefs are a paradise for rock fishermen, providing good fishing even in winter. It is also home to the protected black-tailed Gull; Dongyin Lighthouse, a third class protected historical site, is a fascinating site for those with an interest in culture and history; the Thread of Sky, Yanxiu Echoing Tidal Cave and other natural features are awe-inspiring testimony to the power and majesty of nature. Andong Tunnel, the numerous military camps, forts, and outposts and the camouflaged soldiers give Dongyin a unique military character.