Me and 2 friends (in our mid 20's) are heading to Switzerland for the first time this coming September for almost 3 weeks! We're very active, big into hiking / mtn biking / etc. We'd like our trip to contain a good mix of difficult hiking trails and outdoor activities along with some general sightseeing and touristy aspects. We'll be flying into Geneva in early September and heading East, as we'll be flying out of Munich 3 weeks later (we'll be hitting Oktoberfest for a day or two to end the trip).
Given our active and outdoorsy nature, after Geneva, what are must see areas on our way up to Munich? I've heard great things about Interlaken, Mt Blanc, Grinderwald, Zermatt, etc.
What areas/hiking trails should we 100% have on our list? I know everyone is different but just to give you some context, we love tough hikes similar to what Grand Teton NP offers, Yosemite, Zion, 14's in Colorado, etc...
Also, should we rent a car or use the rail system?
We plan on doing a mix of tent camping/hostel stays. Really appreciate any and all insight!