For all the hype and crowds, Mont Saint-Michel is beautiful and well worth a visit.
If you are under 25 you can get into the abbey for free, and get a half price entry for the four museums (under 18s also free). But be warned - entry is guarded ferociously and you will need to prove your age with your passport. If you leave it in the car (like I did) you'll have to decide if walking back down then back up again is worth the €18 saving!
www.ot-montsaintmichel.com/en/accueil.htm
Porte de l'avancée, 50170 Mont-Saint-Michel
+33(0)2 33 60 14 30
Google map: bit.ly/Mijdpb