The architecture of Mont-Saint-Michel Abbey bears witness to the mastery and craftsmanship of several generations of builders. In the Middle-Ages, its construction represented a technical and artistic feat. It is hard to imagine how such a monument could be erected on this rock of barely 4 km2 and 960 metres in circumference. The Romanesque and Gothic arts were expressed in all their power, resulting in this formidable citadel where the religious and the military are intimately mixed.