Initially built in 1396 in just 98 days by more than 197,000 people, Hanyangdoseong passes through or near eight historic gates, most of which are free to enter. The Seoul Fortress Wall itself runs 18.6 kilometers around the center of the city, sitting high on the mountains of Bugaksan, Naksan, Namsan, and Inwangsan, and dropping low through neighborhoods like Dongdaemun. Along the wall originally stood four main gates and four auxiliary gates, opened and closed each day to regulate movement in and out of the city. Each morning, the Bosingak Belfry bell was rung 33 times to announce the gates opening; each evening, 28 rings announced their closing.
However, during the Japanese colonial period, Japanese overseers had deliberately dismantled several gates — Donuimun and Souimun were destroyed, while Gwanghuimun and Hyehwamun were damaged. Restoration was purposefully neglected until after Korean independence was restored. By 2014, approximately 70% of the wall — 12.8 kilometers — had been restored or reconstructed, and Sukjeongmun, Gwanghuimun, and Hyehwamun had been rebuilt.