Sep 29, 2014 - 5:42 PM
You should travel to Interlaken first. You could do so using the scenic Golden Pass line via Lucerne, Meiringen and Brienz. From Interlaken, you can travel to Lauterbrunnen/Wengen or Grindelwald. From both towns, trains to Kleine Scheidegg leave, and that's where the trains get up to the Jungfraujoch. It would be great to make a round trip, getting up via one route and down via the other. Please find more details on the trip to the Jungfraujoch at the Jungfraujoch page (see the 'How to get there' tab).
Your Swiss Pass offers free traveling up to Wengen/Grindelwald. Between those towns and the Jungfraujoch, a 25% applies. More details on the Swiss Pass are here.
Please make sure weather is clear before getting up to the Jungfraujoch and buying your reduced tickets. It's quite expensive - definitely worth it in clear skies, but not if you end up in the clouds.
I hope this answers your question!
Last modified on Dec 28, 2014 - 4:35 PM by Arno