Toward the end of the Unified Silla period, a monk named Hongcheok traveled to study in Tang China and returned home bringing a new strand of Buddhist thought with him: Seon Buddhism (the Korean equivalent of Zen). In 828 CE, the third year of King Heungdeok's reign, Hongcheok built a temple at the foot of Mt. Jirisan and named it Silsang Sanmun. This became the very first of what would eventually become nine Seon mountain schools — the "Nine Mountain Seon Schools" — established across the country from the late Silla period into early Goryeo. Hongcheok later received the posthumous title of Great Master Jeunggak.
What makes Silsangsa unusual is its location. Unlike most of Korea's famous mountain temples, which sit partway up a slope or tucked into a valley, Silsangsa was built on open, flat land at the base of Mt. Jirisan. Rather than retreating deep into the mountains, this temple planted itself on a broad plain close to where people actually lived — a choice that may reflect early Seon Buddhism's ambition to take root close to daily life rather than withdraw from it entirely. More than a thousand years later, Silsangsa still stands on the same spot, bearing witness to the moment the first of Korea's Nine Mountain Seon Schools opened its doors.