The original name of Gyerim was Sirim (시림, 始林). However, according to the Samguk Sagi, a 12th-century Korean history, Sirim was the site where the child Kim Alji, founder of the Gyeongju Kim clan, was discovered. Found in a golden box accompanied by a rooster, he was adopted by the royal family. His descendants became the later kings of Silla and the forest where he was found was renamed "Gyerim", "Rooster Forest." The "Samgungnyusa", a 13th-century miscellanea of tales relating to the Three Kingdoms of Korea, gives a different origin of the term Gyerim. According to that text, the founder of Silla, Hyeokgeose, was born at a stream called Gyejeong (계정, 鷄井), "rooster well," and that his future consort was born from a dragon that came to earth at another place called Gyeryongseo (계룡서, 鷄龍瑞), and for this reason the area was renamed Gyerim.