_Key to Plan._--A. Tower known as the _Tour Claudine_. Ramparts. B. Barbican. Entrance to the abbey. B´. Ruin of the stairway known as the _Grand Degré_. C. Gate-house. D. Guard-room known as _Bellechaise_. E. Tower known as the _Tour Perrine_. F. Steward's lodging and Bailey. G. Abbot's lodging. G´. Abbatial buildings. G´´. Chapel of St. Catherine. H. Courtyard of the church, great stairway. I. Courtyard of the _Merveille_. J, K. Almonry, cellar (of the _Merveille_). L. Formerly the abbatial buildings. M. Gallery or crypt known as the _Galerie de l'Aquilon_ (of the North Wind). N. Hostelry (Robert de Thorigni). O. Passages connecting the abbey with the hostelry. P, P´. Prison and dungeon. R, S. Staircase. T. Modern wall of abutment. U. Garden, terraces, and covered way. V. Body of rock.] [Illustration: 151. ABBEY OF MONT ST. MICHEL. PLAN AT THE LEVEL OF THE LOWER CHURCH, THE REFECTORY, AND THE CHAPTER-HOUSE, OR KNIGHTS' HALL.--_For Key to Plan see opposite page._ _Key to Plan._--A. Lower church. B, B´. Chapels beneath the transepts. C. Substructure of Romanesque nave. C, C´, and C´´. Charnel-house or burying-place of the monks, and substructure of south platform. D. Formerly the cistern. E. Formerly the claustral buildings. Refectory. F. Formerly the cloister or ambulatory. G. Passage communicating with the hostelry. H, I. Hostelry and offices (Robert de Thorigni). J. Chapel of hostelry (St. Étienne). K, K´, L, M. Refectory. Tower known as the _Tour des Corbins_ (Tower of Crows). Chapter-house, or hall of the knights, Galilee or narthex (_Merveille_). N. Hall of the military executive, or hall of the officers. O. Tower known as the _Tour Perrine_. P. Battlements of the gate-house. Q. Courtyard of the _Merveille_. R, S. Staircase and terrace of the apse. T. Courtyard of the church. U. Fortified bridge connecting the lower church with the abbey buildings. V, X. Abbot's lodging. Accommodation for guests. Y, Y´. Cisterns of the fifteenth and sixteenth centuries. Z. Body of rock.]