Putuo is the pilgrimage centre of Guanyin, and Guanyin is the site of one of the largest transformations in Buddhist history.
Avalokiteshvara becomes Guanyin
In Indian sources, Avalokiteshvara, the bodhisattva of compassion, is male. In Tibetan tradition he remains male, Chenrezig, of whom the Dalai Lamas are held to be emanations.
In China, over roughly the tenth to fifteenth centuries, the figure became overwhelmingly female.
The change was not decreed and did not happen at once. It appears to have proceeded through local cults (notably the legend of Princess Miaoshan, a king's daughter who refuses marriage, is persecuted by her father, and gives her eyes and hands to heal him), which attached themselves to the bodhisattva and gradually reshaped the iconography. By the Ming, the female form was standard.
Chun-fang Yu's study of the process is the standard treatment. It is one of the clearest documented cases anywhere of a major deity's gender changing through popular devotion rather than doctrinal decision.
The consequences were large. A compassionate female figure who responds to those who call on her, grants children and rescues from danger occupied a place in Chinese religion that nothing else did, and Guanyin devotion crosses Buddhist, Taoist and popular boundaries freely.
The island
Putuo is an island of about twelve square kilometres in the Zhoushan archipelago, identified with Potalaka, Avalokiteshvara's mountain island in the Indian sources.
Three great temples anchor more than thirty others: Puji (tenth century), Fayu (1580) and Huiji (1793). A thirty-three-metre Guanyin faces out to sea.
The Guanyin Who Would Not Go
The island's founding story concerns a Japanese monk, traditionally Egaku, carrying an image of Guanyin home from Wutai in the ninth century. His ship was turned back repeatedly by storms until he accepted that she did not wish to leave.
The temple built for her is still called Buken Qu Guanyin, the Guanyin Who Would Not Go.
It is a founding legend that explains a pilgrimage site by the deity's refusal to be taken elsewhere, which is neat, and it also records the fact that Putuo sat on the sea route between China, Korea and Japan and drew traffic accordingly.
Practice
Pilgrimage peaks on the nineteenth days of the second, sixth and ninth lunar months, Guanyin's birth, enlightenment and renunciation.
Private cars are banned; everyone arrives by ferry. The Buddhist Association of China oversees the religious buildings, as at every registered Buddhist site in the country, so the island operates under state supervision alongside monastic administration.