the Jin-gam biseok [biographical steele]
written by Choi Chi-won  at Ssanggye-sa
고운 최치원 진감선사대공탑비석  National Treasure #47
Choi Chi-won is one of my favorite figures of Korean cultural
history, displaying many virtues & talents and symbolizing
many key themes.  He was born in 857 on the north-
eastern-most slope of sacred
Nam-san [South Mountain] in
the Unified Shilla Dynasty's capital Gyeongju.  He grew up
as a prodigy during the kingdom's steep decline from a
world-class trading, military and religious power into utter
civil and political collapse.  He went to China to further his
studies, and was so talented that the also-declining Tang
Dynasty employed him as an official.

Finally returning to Shilla, Choi did his Confucian best to
save the kingdom by advocating reforms, but they were
unfortunately rejected or ignored.  Despairing that the
necessary reforms could ever be implemented, he left the
capital and "washed his ears" of its corruptions in the pure
waters of the deep remote gorge north of
Ssanggye-sa and
east of
Chilbul-sa which thereafter became named
Daeseong-gyegok [Great Sage Scenic-Valley] in his honor.

He spent his later years wandering the southern third of the
peninsula, visiting sacred sites and holding discussions with
their monastic residents, learning, practicing and teaching
Daoist techniques of longevity / immortality, and composing
historical records of Korea's greatest temples.  He met and
learned from
Doseon-daesa, Buddhist Master of Geomancy.
He took the scholar-name
Go-un [Lonely Cloud] to reflect
his feelings about his life in effective internal exile.  Many
southern sites boost their prestige by claiming to have been
visited by him, such as the
Shinseon-dae [Platform of a
Spiritual Immortal] bluff on the south coast of Busan City.
the portrait of Choi Chi-won above is in
Ssanggye-sa's
Seongbo Museum, age
unknown.  Portraits of him are very rare.

I'm sorry for the bad photo, but i had to shoot it
through a reflective glass case.
Choi is credited with naming Busan's famous Haeundae
Beach by carving those characters, meaning "Sea Clouds
Platform", on a rock beneath the pavilion he had built
overlooking it.  Also with designing the unique Gate-Hall
straddling the stream in Goun-sa Temple south of Andong,
the superb dragons-dancing-in-the-clouds capstone features nine
elaborate Chinese characters in moderately primitive script
The text Choi wrote on the stele body tells the early history of Ssanggye-sa, the
biography and accomplishments of Jin-gam-daesa (a great Master of Meditation
of the early 800s, including his establishment of Beompae (Korea's Buddhist
ritual-music-&-dance) and nurturing Korea's first green tea field just outside this
temple starting in 828.  This monument was built under the patronage of King
Jeonggang (r.886-887) who highly respected Jin-gam-seonsa.
which then took his pen-name for its own.   He is said to have lived for awhile nearby the great  
Gaya-san Haein-sa monastery and writing its history -- he may be enshrined there before Haein-sa's
front gateway,
as a guardian spirit similar to a San-shin.   Certainly his most famous physical legacy
is this magnificent monument with extensive inscription in his own "lively" calligraphy.  He is credited
with composing many fine poems, essays and other feats of spiritual scholarship.  It is said that he
never actually died, but rather achieved
shinseon immortality at Gaya-san's peak in the early 900s --
intuiting that Shilla was at its end, he bid the others at the temple farewell and went off hiking.  Days
later monks went up to search for him, but they only found his straw sandals and hat.

In the subsequent dynasties, Choi Chi-won was honored as highly as a non-royal citizen could be.
His family's house and birthplace on the northeastern corner of
Gyeongju Nam-san was turned into
a shrine, enlarged and expanded several times by the decrees of kings.  On that ancient capital's
western sacred mountain,
Seondo-san, a noted Neo-Confucian scholar established the Seo-ak
Seowon
[West Peak Private Confucian Academy] which enshrines the three most accomplished
personages of the Shilla Kingdom who were not kings -- General Kim Yu-shin, Scholar Seol Cheong
and Choi.  Both of these places are a bit obscure but can still be visited by intrepid travelers today.
Myself respectfully studying this monument, in Jan 1987!