Chamonix is a long 5+ train ride from Interlaken via Montreux/Martigny. The Mt Blanc express (basically a cog wheel) from Martigny is a long ride but the beauty makes up for all. Once there another must do is the Aiguille de Midi. As is the Brevent cable car. Both are all day affairs because of the beauty. Chamonix is very trendy and even had a late night rock concert in the main square for all to engage. Outdoor cafe’s abound.