Any suggestions as to which train station to depart from when traveling from Paris to Bayonne?
Montparnasse
To clarify: you do not really have a choice. Each region of France is served by one, and only one, Paris station (with minimal exceptions). Montparnasse, in the case of Bordeaux and beyond (incl. Bayonne)
thank you
I have friends in France whom I visit on every trip. Trains to their town leave from Gare Montparnasse, so I stay in that general area. That way it's easy to walk to the station, very helpful for early morning departures.
And if you want to know which Paris station that serves a particular area, here is a great map: https://commons.wikimedia.org/wiki/File:Railway_stations_on_departure_from_Paris_map-en.svg