Get the fast train in and out. Not a lot to see in Taiyuan, but trip to Pingyao is wortha visit.
Out from Datong you'll find the Grottoes and the Hanging Monastery but both Taiyuan and Datong a re coal cities and as such are very unappealing.
Tip, you have one too many 'a's in Shanxi.
Shaanxi is the province to the south and home to Xi'an and the warriors, etec. over 7 years ago