SEOUL—The leaders of North and South Korea stood atop a volcano, smiling and joining hands, ending a three-day summit heavy on symbolism with a pilgrimage to the 9,000-foot peak where the first Korean kingdom is reputed to have been founded.
Mount Paektu, which straddles the China-North Korea border and is known as Mount Changbai in China, holds a venerable place in Korean folklore. It features prominently in the North’s propaganda, which extols the mountain as the birthplace of Kim Jong Il, the father of current leader Kim...