While in Switzerland for 15 days, I would like to take a train from Basel to visit Colmar (and stay there one night). I will then return to Basel by train and continue with my vacation time in Switzerland.
Questions: I will have a 15-day Swiss Travel Pass; will this STP entitle me to a free ride from Basel to Colmar? Meaning: I just hop on to the train with my STP? If so, then, can I book my return ticket while in Basel? Is this allowed? Meaning: If I book the return-trip ticket while still in Basel, when I board a train at the Colmar station to return to Basel, will I have to do anything at the Colmar station before I get on a train?
Thank you for your help.