A wonderful experience. There's a 1960s resort hotel built for the springs, with all the…read moretreatments, elegant rooms (get one in the refurbished wing) and a very good (grand-hotel style) restaurant. Then, the spa itself is an amazing building built by Peter Zumthor (Google it) entirely out of the local rock. He has created an unforgettable experience. Try swimming out though a quartzite rock doorway into the heated pool at night and sit in the steam looking at the snow and stars.
On the other hand, you're in a rather ordinary little Swiss village, so if you want to leave the hotel there's not much to see unless you want to go hiking. Bring books and a swimsuit.
You can get there pretty easily by (very efficient) public transport: train from the airport, changing several times, and then a bus taking a spectacular route winding through the valleys.