While it is well-known in the Republic of China that the nation's territory stretches south all the way to James Shoal, few know that the northern limits reach all the way to Dongyin Island in the Matsu Island chain.The nor thernmost point itself is on Xiyin Island, 600m from Hou'ao, at BeiguReef. This place is not always visible, coming above and dipping below the seawith the tide. Yet to mark the nation's nor thernmost point, a monument hasbeen installed at Hou'ao so that visitors can take pictures and say that they havebeen here if they haven't seen Beigu Reef.