The Cellar is formed by three naves with the roman plain groined vaults pointed and very acute in the two lateral naves rest on square pillars supporting the columns of the knights’ hall above. It is lighted by five narrow pointed windows situated between the buttresses. Towards the west, a large door opens on the terraces and gardens below. It probably established communication between the Cellar and the Hall, built and destroyed, or simply began by Richard Tristan in the second half of the XIIIth century.
In the second transverse compartment, towards the west and under one of the windows was placed a low door which opened on a draw-bridge made between the two buttresses and of which the arch which supported it when it was clown can be still seen. This draw-bridge, making a projection on the front of the wall in order to cut its sloping base, was used to bring up, by a wheel placed in the Cellar, the water is taken from the fountain Saint-Aubert, situated at the foot of the rock, and which was stored in the Cellar for the wants of the Abbey.
The Cellar was called Montgommerie or Montgommery since the unsuccessful attempt made by this partisan in 1591 to seize by surprise Mont Saint-Michel. It had been a disappointing venture and left on of his men with an arrow through his chest, though they are not sure how it happened. They thought it must have been a stray shot from one of their own archers who had missed their mark. Though he did not know these hills nearly as well as the Normans, he knew that there were people living nearby and perhaps more enemies than just those at the abbey up on top of the hill. He hoped for once that someone would come out and fight them but no luck so far; they seemed intent on staying hidden behind their walls and gates
We find in one of Dom Jean Huynes’s manuscripts curious details of the attempts of the Huguenots during the wars of the League to seize upon the Abbey. On the right of the west gate, the staircase built-in the thickness of the buttresses leads to the Knights’ hall above.