Yong‘an Temple at the foothills of Heng Shan (恆山) only unlocks its halls when there are visitors and for a good reason – this poised and serene 13th-century temple is the home of some of the most precious Yuan dynasty coloured frescoes in China. You don't have to be an expert to appreciate the 200m of paintings on the interior walls of the main hall: gorgeous, fragile and surprisingly vivid, quietly telling their religious and secular stories in the half-light.
The temple sells exquisitely printed scrolls of the frescoes with descriptions. Scroll booklets (in English or Chinese) are ¥50 each; and there's a large deluxe box-set with several metres of scrolls that sells for over ¥9000.
Buses depart for Hunyuan (浑源) from Datong’s main bus station (¥31, two hours). A cab ride from downtown Hunyuan to the temple costs ¥50.