The Swiss Travel System is incredibly comprehensive and includes rail, lake steamers and city transportation lines.
You'll want to take advantage of the Golden Pass Panoramic Tour which is one of the most scenic tours you can take in Switzerland.
The tour starts off in beautiful Montreux Switzerland and winds it way up the moutainside through the tiny Montreux villages and scenic view of the beautiful Lake Region of Lake Leman. At Col de Jaman, the train plunges through a tunnel into the mountains, changing valleys and heading for the world famous resorts of Châteaux d’Oex and Gstaad. You'll pass such famous picturesque towns as Gruyere, and Gstaad on your way to your train stop in Zweisimmen.
The line attains its culminating point (1,274m) before reaching Zweisimmen, from where the traveller can continue the trip with the GoldenPass Panoramic towards Interlaken and Lucerne.
It's worth your time to check out Switzerland by Rail