Choryang Waekwan was the biggest Japanese settlment to house the Japanese diplomatic mission and traders in Korea. Waekwan means Japanese Pavilion literally, but the reality of this Waekwan exceeded much the scale of single architecture. Since Choryang Waekwan was closed in the second half of the nineteenth century, the site of this settlement grew rapidly as the downtown of Busan, which was the first port open to foreign countries in modern Korea. The formation of modern port owes much to the presence of Japanese settlment in Lee Dynasty as long as Choryang was officially designated as the trading port toward Japan and vice versa. Busan is the nearest city to Japan, in fact. Within a day ships could reach Tsushima Island, the island region north of Fukuoka, which played an intermediary role between Seoul and Edo. No architectural remain could be seen on the actual site of Choryang Waekwan. The site has become one of the busiest centers in Busan with quantify of office buildings and shops. The former Busan City Hall was located in this area. The field survey of the site as well as the analysis of historical documents, which were newly found both in Korea and in Japan, enabled to reconstruct the architecture and cityscape of Waekwan by way of computer graphics.