In 1884, King Gojong decided to launch a modern postal service system. To achieve this, Ujeong Chongguk (Historical Site No. 213) was established, with the agreement of the Vice Minister of War, Hong Yeong-Sik, who had long desired such a postal system. Ujeong Chongguk is the world’s oldest post office and the first post office of Korea’s modern postal service. Originally built in a style similar to that of Jeonuigam, the palace medical office in the Joseon period (1392-1910), the Ujeong Chongguk building is an example of the architectural style of the late Joseon period. It covers an area of 5 kan (1 kan is equivalent to roughly to 5.876m2) by 3 kan and consists of granite column and round and square columns with a hip-and-gable roof. Founded by King Gojong, Ujeong Chongguk opened in November 1884. However, on December 4, 1884, when the opening ceremony was scheduled to be held, a group of reformers, including Hong Yeong-Sik, who was also the first president of the post office, staged a coup. The coup ended in failure three days later, and the operation of the post office was suspended 20 days later and eventually closed. The world’s oldest post office and Korea’s first postal administrative office, Ujeong Chongguk is a living witness to the history of the modern postal service and the origin of the over 3,600 post offices nationwide.