Chojijin Fortress is believed to have been built in 1655 (6th year of King Hyojong) for the purpose of national defense against coastal attacks from foreign enemies based on articles regarding the construction of Chojijin Fortress. The fortress was the scene of many hard-fought battles including the invasions of America and Japan in the 1870s. The site was then taken by the foreign troops due to the inferior fighting power of the Korean military, and very nearly completely destroyed. In 1876 (13th year of King Gojong), the Japanese warship Unyangho invaded and forced the Joseon Kingdom to open their ports, which later led to the forced signing of the Jana-Korea Treaty of 1876. Only the base of the fortress and the site of the high ground remained until 1973, when restoration work was started. The patriotic spirit of the Joseon dynasty still remains in this historic site.