Mont St- What's it called again?

"Its called Mont-Saint Michel Emma". A picturesque abbey and tiny medieval town upon a hill across a causeway (actually a building site that looks like a motorway is going to run straight up there).  

An afternoon was enough time so we decided to head on southwards towards Bordeaux taking a lengthy detour to Chateaubrand for lunch, a pleasant town with a beautiful castle. Very good food and now onwards..................