Early references to Penglai appear in Warring States and Han period texts, including the Liezi, which describes it as one of five mountainous islands rising from the Bohai Sea, populated by immortals and animals of pure white, with towers and terraces built entirely of gold and jade, and trees bearing pearls and gems instead of ordinary fruit. A crucial detail recurs across the sources: the island, unlike an ordinary geographic destination, is said to withdraw from any vessel that draws near it, so that repeated determined attempts to reach it by sea consistently and mysteriously fail, a feature that functions less as a navigational obstacle than as a built-in guarantee that the place remains permanently just beyond mortal reach.
Sima Qian's Shiji records that the First Emperor of Qin, obsessed with achieving personal immortality, sent large, lavishly funded naval expeditions in search of Penglai and its elixir of deathlessness during the third century BCE, most famously the voyage led by the court alchemist Xu Fu, who reportedly departed with thousands of young men and women and enormous resources and never returned to report success, a story later legend in Japan and elsewhere has connected, without firm historical proof, to the founding of settlements abroad.