evidence: The Noktundo region and the Tuman River estuary have been under Russian control for nearly 200 years . When the Soviet Union was doing well, in the process of establishing the border between North Korea and the Soviet Union, North Korea recognized the land at the mouth of the Tuman River, including the Noktundo region, as Soviet territory. Even after the collapse of the Soviet Union in the 1990s, North Korea again recognized the land at the mouth of the Tuman River, including the Noktundo region, as Russian territory. Therefore, the assumption that the Russian Federation government will give up Noktundo is unrealistic. [...] In conclusion, Noktundo Island is recognized as Russian territory from an international law perspective, and there is insufficient evidence and justification to support the South Korean government's claim of sovereignty. From a practical perspective, Noktundo Island is nothing more than a wasteland of low value, and it is not worth trying to recover it by causing friction with Russia, with which South Korea maintains a good economic and diplomatic relationship. However, based on the recently raised Soduman River boundary, the area of Noktundo Island is approximately 400㎢, which is 12.5 times the existing boundary, which is almost the same as the area secured by Saemangeum , the largest reclamation project in South Korea (409㎢), and it is about 2/3 the size of Seoul, and it should be kept in mind that the area bordering the sea has also increased, which can help secure territorial waters .