Taejo of Joseon
On January 1, 1396 (by the lunar calendar), Taejo of Joseon held the groundbreaking ceremony. 197,400 young men were placed under civil conscription over two years and completed building the castle 98 days after the war along the mountains Bugaksan, Naksan, Namsan, and Inwangsan. The wall contained eight gates, all of which were originally constructed between 1396 and 1398.