Europe is full of must-sees. However, some of the best places are those that are real because time or technology has passed them by.
Sion is one of those places. It is a 21st century town with plenty of telephones, fast food joints, and shopping. However, it goes at a slower pace than the rest of Switzerland and feels like France. Patisseries are along most streets; boulangeries can be found without looking too hard. The main goal of the day is to enjoy the weather, a good glass of wine and good conversation. The locals are very warm and friendly. When my wife and I couldn't find the grocery section of the Co-op, we were shown the way to go, and when we couldn't figure out how to weight the fruit, we were shown that as well.
I wouldn't make Sion a destination, but when you need a vacation from your vacation, Sion might be the place for you. You can enjoy the valley and if you are inclined, several small villages are up in the hills and plenty of hiking or skiing could be yours for the taking.