Hyehwa Moon, also known as Hyehwamun, is one of the gates of Seoul's old city wall. It sits on the edge of Jongno-gu and Seongbuk-gu, making it a useful landmark if you are tracing the wall or exploring the quieter northern side of the old capital.
Hyehwa Moon
Historic Seoul city-wall gate between Jongno and Seongbuk