The flag of Seoul, used from 1 April 1947 to 28 October 1996. The old emblem was chosen through a prize contest to commemorate the renaming of Seoul "Seoul Free Special City" on Sept. 28, 1946, and had been used since April 1, 1947 until it was replaced by the new one. The circle in the center of the emblem represents street. and the octagonal symbol stands for eight mountains surrounding Seoul: Nam-san, An-san, Inwang-san, Pukak-san, Nak-san, Muhag-bong, Wau-san, Ung-bong.
Own work
AnonMoos (earlier non-vector versions by  Jedan02)