Although a touristy town, Grindelwald makes a perfect base for a good week's worth of walking with footpaths in all directions from the town and the ability to do circular routes. The walking can be as demanding as you wish. Needless to say the views are great.
www.grindelwald.com
www.sbb.ch
www.jungfraubahn.ch/en/DesktopDefault.aspx/tabid-138/
www.sonnenberghotel.ch/