Switzerland had private rail companies as well as the SSB and most of the private companies don't take the interail pass. Zermatt - Visp us one if those. However it was only about £20. Form Visp I had two other trains to catch that took me to Inter lake. Fron here to Grindelwald was around £8
I think I saved the best til last.
Walking from the station I was surrounded by mountainted, including the Eiger
I quickly checked in and went for a hike, catching the lift
The scenery. ....!
Absolutely breathtaking. The hotel is one of the best as well. I have tried to stay in hotels within a 15 min walk from the station in the mid-budget range, around £60 (this is quite tricky in Switzerland! ! ). This one has a south facing balcony : if only I were here for more than one night!
I only booked Grindelwald because all the mud budget hotels in Interlaken were taken: what a blessing in disguise. I would love to return; maybe in the winter!