No matter how many pictures of it you may have seen beforehand, your first glimpse of the iconic Xuangkong temple outside Datong is guaranteed to evoke gasps of amazement. Clinging to a near vertical sandstone escarpment, 246ft (75m) off the floor of a hidden valley, the upswept roofs and wooden galleries of the shrine have hung precariously over the same void for nearly 1,500 years. Oak beams driven into post holes in the cliff provide support for this gravity-defying edifice, whose halls, hollowed from the rocks, contain Buddhist, Daoist and Confucian deities.