Grimsel pass is in middle of Switzerland, next to the Furka Pass, and separates the Upper Rhone Valley from the Bernese ALps and the Upper Rhine Valley.
Some very good multipitch sport climbing at high level of exposure of 500 meters or more can be found around Rosenlaui (see Wellhorn, Kingspitze etc). Mountaineering adventures abound as well in a quintessential alpine environment.
Grimselpass in the granite paradise with such areas as Eldorado offering top classics with approach or Handegg with less walking but still at least 10 pitches of climbing. A lot of work by Remy brothers went into developing these areas. Respect and thanks!