This museum makes for a nice diversion. The 1st floor has English interpretation signs, and there are several movies to watch. The 2nd-floor display of salt crystals from around the world is fascinating in its variety. It's closed on the third Wednesday of the month.
The museum and the Cigu Salt Mountains are off Hwy 17 north of Tainan. The turn-off is marked with English signs at around the Km156 mark.