About this Holiday
National Foundation Day commemorates the legendary founding of Gojoseon, the first Korean kingdom, by Dangun Wanggeom on October 3, 2333 BCE, as recorded in the Samguk Yusa. The name 'Gaecheonjeoil' (開天節) means 'Day of Heaven Opening,' celebrating the founding ideal of Hongik Ingan — benefiting all humanity. Ceremonies are held at Chamseongdan Altar on Manisan Mountain on Ganghwa Island and at Dangun shrines across the country.