Han-Shan was a Chinese Buddhist poet who named himself after a place in China where he lived called Cold Mountain (the translation of Han-Shan). His date is unclear, although stylistically he appears to be in the T’ang Dynasty, perhaps 700-780 CE. He is considered one of the greatest poets of classical Chinese poetry.
The poet Gary Snyder translated a few of Han-Shan’s poems,1 and has reproduced a contemporary account of the poet by a visitor. Nothing is known of his early life before he arrived at Cold Mountain. He lived the life of a homeless monk in the neighborhood of a Buddhist temple, where he obtained food and talked with the monks. He disappeared, and the visitor copied the poems that he had written on the walls of houses, cliffs, bamboo, wood and stones, about 350 poems in total that have been passed on through the generations.
In the Columbia Book of Chinese Poetry, from Early Times to the Thirteenth Century, edited and translated by Burton Watson, Mr. Watson says the following about Han-Shan:
“The poems themselves, however, are by no means uniformly jolly in tone. Rather they reveal a man at times deeply contented, even rapturous with the delights of his mountain retreat, at other times troubled by privation and nagging loneliness. Underlying them throughout is the Zen – or more correctly, the Mahayana Buddhist – conviction that these very experiences of daily life, painful or peaceful, harsh or serene, are the stuff that enlightenment is made of. There is, in other words, no Way outside of the way of everyday life.”
Here is one of his poems, from the website poetryintranslation.com2:

Where’s the trail to Cold Mountain? Cold Mountain? There’s no clear way. Ice, in summer, is still frozen. Bright sun shines through thick fog. You won’t get there following me. Your heart and mine are not the same. If your heart was like mine, You’d have made it, and be there!
1Riprap and Cold Mountain Poems, by Gary Snyder, Counterpoint Press, Berkeley, 2009.
2Words from Cold Mountain, Twenty-Seven Poems by Han-Shan, translated by A. S. Kline.