This is a fortress built of stone with a total length of 18.845m for the purpose of territorial and coastal defense in 1703, the 29th year of the reign of King Sukjong, a time of growing consciousness of the importance of national defense following the experience the Japanese invasion of Korea in 1592 and the Manchu Invasion in 1636. There are two different but related records with regard to the period of its construction in one chronicle called Jeungbo munheonbigo (The Revised and Enlarged Edition of the Comparative Review of Records and Documents): one, a note of the building by order of Park Tae-hang and the other, regarded as earlier than that of Park, of a recommendation (for the reconstruction of this fortress) by Yi Ji-hyeong, a commander-in-chief of the naval forces, to King Hyeonjong in the 8th year of his reign. The real period of the construction to this fortress, therefore, might fall on the side of Yi Ji-hyeong. The fortress is located at an advantageous position for observation of the lower region of the Nakdonggang River and of Dongrae district (now a part of Busan), and especially for watching watching out for attacks by foreign countries like Japan through the marine passage. The scale of this fortress and the mode of constructi its walls have some experts infer a later period for the beginning of its construction than hypothesized on the basis of the records from the historical material above. In the 33rd year of King Sukjong ‘s reign (1707), the inner wall dividing the north and south sections was erected due to dominant opinions that the area of fortress was too large to be effectively managed. It was for instance closed for the same reason explained above in the 50th year of King Yeongjo’s reign (1774). In the 6th year of the reign of King Sunjo (1806), the fortress was partly rebuilt and reinforced with natural granite, but it was largely demolished in the period of Japanese colonization. Repair work started in 1972, completing the restoration of the old regime of gates in the east, west and south in 1974, and in the north in 1989. The walls still remaining reach a length of 4km. The historic significance of the place lies in the fact that its ruins tell us about the structure of large-scale defense positions around the fortress in the late Joseon Dynasty and that it shows us the form of the largest fortress in Korea.