Case file · Folklore / legend
Grotto-heavens of the Taoist immortals
Taoists believed that certain caves and mountain hollows, the dongtian or 'grotto-heavens', held hidden paradises between heaven and earth where immortals lived amid strange flowers and peach trees.
735 CE · 31.75, 119.33 · status: legend
The account
In the Tang dynasty Sima Chengzhen (647–735) and later Du Guangting listed ten greater and thirty-six lesser grotto-heavens, many on sacred mountains such as Maoshan. Hermits seeking immortality retreated to such caves, and some mountains still host recluses today.
The sceptical view
A religious cosmology rather than a claim of physical beings; the caves themselves are real pilgrimage sites.