We are based in Paris. Realistic to take an early train to Normandy, then later in the day take another train to Mont Saint Michel, return back in Paris very late that evening? One day trip only. Thanks!
Where in Normandy, which is huge, do you plan to go? There is no train to Mont St Michel from anywhere, by the way.
Probably the only way would be with a car... but all you would be doing is driving. I have spent time at both places and driven but would definitely not do both in one day. Each deserves more time. If you can only do one day I would choose just Normandy. I assume you mean the American Cemetery...
You will only have time for one of those day trips. There is no train to the Mont but you can easily take a train to Bayeux and meet up with this wonderful guide for a Normandy Beaches tour. My husband and I took his full day tour a few years ago. It was the most memorable part of my trip to France. I just checked to see if Roel is still leading travelers around Normandy and was very please to see his is as popular as ever.
Not realistic at all. If you want to see anything in Normandy, you need a full day.
Trains from Bayeux to Pontorson-MSM only run 3x/day, departing around 7:30, 14:20, and 17:45, so you at least have to spend a night in either location to see both quickly.