The Aletsch Glacier is the biggest glacier in the Alps (
The route is good for beginners...it starts easy and stays easy for a while. The tricky bit, if you could call it so, could be the longest suspension bridge in the Alps! It bounces a little over a raging river, even though there is a solid walkway rather than a single braided wire like some routes have. Don't look down, newbies.
The return side of the route is a little bit more interesting and challenging, and maybe even lives up to the rating of 3-4. I think the whole thing is more like a 2, with an occasional adrenaline filled traverse. Fun but after doing the Kandersteg route a few days ago, it felt too easy! There is a short zipline, too, but you'll have to bring your own pulley if you want to do it. Overall, a fun little route above the town of Blatten near Brig in Switzerland.