It is believed that he walked the entire length and breadth of the Korean peninsula, through mountain and valley, in order to research and compile his magnum opus, the Daedongyeojido, (대동여지도, 大東輿地圖) a map of Korea that was published in 1861, from which was subsequently made a single-sheet version, the Daedongyeojijeondo (대동여지전도 大東與地全圖).