Datong is definitely the dirtiest city I went to in China. In the city itself breathing sometimes really hurt and there was black coal smog everywhere around you. However, the sights around the city were really nice and the Chinese there reacted to foreigners like we were giraffes being seen for the first time ... On one of the pictures one of the girls gets advice for her future marriage from the bearded temple man. The way back taking a whole night on hardseat ticket for 2.70 Euro was an experience in itself ;-)