Prince Yongsan (Korean: 용산원자; Hanja: 龍山元子; lit.
Primary Son Yongsan; 1325–1341) was a Goryeo royal prince and the heir to the throne as the only son of King Chungsuk of Goryeo and Princess Joguk.
[2][3] According to Goryeosa records written by Jeong Bang-gil (정방길) in 1330,[4] it was said that the Prince didn't have a good relationship with his half older brother, the 16 years old Prince Wang Jeong who was 10 years older than Yongsan.
Then, Bang-gil told Wang Jeong who wanted go to Yuan dynasty for join with Prince Yongsan to go there, but Jo Ik-cheong (조익청) said "It's Impossible" (불가하다) and he then stopped it.
After his death, his body was transported to Goryeo for the funeral, but his tomb site was unknown because no records left about that.