Seoul, South Korea is a vibrant city where old meets new and the traditional meets the modern. One of the best ways to experience this interplay is along the old city wall. There is a trail, the Seoul Seonggwak trail (서울성곽길), that follows what is left of the wall and follows fairly closely to where the wall use to be.
The old city of Seoul was once surrounded by a fortress wall. There were four main gates that were built in accordance with the traditional practice of geomancy. There were also several other smaller gates. Today only three of the four main gates remain. Seodaemun was destroyed during the Japanese occupation. The two most prominent gates are Namdaemun, or Sungnyemun, and Dongdaemun, or Heunginjimun.
http://seoulcitywall.seoul.go.kr/front/eng/sub01/sub0101.do
