The Silsangsan sect was headquartered out of Silsangsa Temple, or “True Nature Temple” in English, in Namwon in present-day Jeollabuk-do in the northern part of the famed Jirisan National Park. The founding patriarch of the Silsangsan sect was Hongcheok-guksa (fl. 830 A.D.), who built Silsangsa Temple to help spread the teachings of Seon Buddhism. Hongcheok-guksa learned under Zhizang (735-814 A.D.). The sect was first founded in 828 A.D. Hongcheok-guksa was posthumously named Jeunggak. Both Hongcheok-guksa’s stupa and stele can be found to this day on the temple grounds of Silsangsa Temple.
In the early 800’s, Hongcheok traveled to Tang China (618–690, 705–907 A.D.). He did this to help further his Buddhist studies. While there, he studied under the monk Zhizang. Hongcheok-guksa returned to Silla at the beginning of King Heungdeok of Silla’s reign which lasted from 826-836 A.D. Upon his return to Silla, Hongcheok-guksa was able to convert King Heungdeok of Silla and his heir, Seonggang. Silsangsa Temple was later renovated by royal decree around the time of King Heungdeok of Silla’s reign. It was then that the temple became the centre of the Silsangsan sect. Master Hongcheok had numerous disciples including Pyeonnum and Sucheol. Of note, the Silsangsan sect was the first of the Nine Mountain Schools.