How to travel from Basel to Saas Grund

Dear Hammer8, both routes can be completed within one day, but if you use the Swiss Card, this requires you to take the shortest route (the one offered to you by the Swiss time table). This would be the first route via Bern and Spiez (the train doesn't pass Interlaken), taking about 3 hours.

The second route is actually a detour. Just as with the first route, you will eventually end up in Spiez as well and take the same route from there. The section between Lucerne and Interlaken, via Brienz, indeed includes a beautiful ride over the Brünig Pass along several lakes. This route would take 5h31 and can still be completed within one day (in Swiss Card terms, this is one date and not 24 hours). If you'd prefer this option, you would need either a Swiss Pass or a Swiss Flexi Pass, which doesn't require you to take the shortest route.

If your inbound and outbound journey are the only longer train journeys of your stay, you shouldn't buy a Swiss Pass. You may consider a 3 day Swiss Flexi Pass, which would offer you an extra day of free travelling. The price difference between a 3 day Swiss Flexi Pass and a Swiss Card is CHF 67,-, so if you would make one trip that would cost CHF 67,- less with your Swiss Flexi Pass during your stay this would be worth the extra money you'd spend. Prices of regular journeys can be checked by filling out the trip in the online timetable.