The church or Basilica has always been the center and, as it were, the heart of the Abbey. It is the oldest construction of the Mount; the different buildings and the town itself has been successively grouped around it: and they make a majestic basis for the old sanctuary of Saint-Michel and form by their assemblage a magnificent whole as wonderful by its picturesque situation as by the boldness of its conception and the great beauty of its details.
It seemed to us necessary to begin the visit by the church, in order to be able to describe clearly the edifices of different epochs, which are placed one over the other, and to lead our reader in the turnings of so complicated a labyrinth.
Although this manner of proceeding is not in conformity with the details of the description of the topography of the Mount, yet it has seemed to us the most rational and the most useful, because it will allow us to follow the construction of the Basilica, of the buildings of the Abbey and of the Ramparts.
These drawings, by giving the right idea of the plan of the buildings placed one over the other, of their grouping and of their forms, at different levels, will help to guide the visitors without confusion in the maze of their innumerable divisions.

EXPLANATORY NOTE
A — Claudine tower. — Ramparts.
B — First fortified enclosure, or Barbican, surrounding the Châtelel and protecting the entrance to the Abbey.
B’ — Ruins of the large flight of steps.
C — Châtelet, — Lower part, staircase overlooked by the Châtelet and leading to the Guard Room.
D — Guard Room (Belle-Chaise).
E — Perrine tower.
F — Proxy’s office and Baillif’s office of the Abbey.
G — Abbatial dwelling.
G’ — Lodgings of the Abbey.
G” — Sainte-Catharine’s chapel.
H — Churchyard and staircase leading to the higher church.
I — Court of the Merveille, — between Belle-Chaise and the Merveille.
J — Armory Room
J’ — Ruins of a furnace
K — Cellar
L — Old abbatial dwellings. — Kitchens — (End of the XIth century).
M — Gallery or Crypt of the Aquilon (Roger IF).
N — Basement of the Hostelry- (Robert de Torigni).
O — Passages communicating with the Hostelry.
P and P‘ — Prisons.
Q — Bases of Saint-Stephen’s chapel.
R — Ruin of the old poulain (Robert de Torigni).
S — Modern Poulain.
T — Wall supports, built-in 1862 or 1863.
U — Gardens, terraces, and narrow path round them.
V — Solid rock.

EXPLANATORY NOTE
A — Lower church or crypt, called the great pillars.
B — Chapel under the north transept.
B’ — Chapel under the south transept (Saint-Martin).
C — Basement of the romanesque nave.
C‘ — Charnel-house or Cemetery of the monks.
C” — Romanesque under-basements (under the platform called Saut-Gaultier)
D — Old cistern.
E — Old abbatial buildings. — (Refectory). — End of the XIth century.
F — Old cloister or walking-place (Roger II).
G — Passages communicating with the Hostelry.
H — Hostelry
I — Outbuildings of the Hostelry
J — Saint Stephen’s chapel.
K — Refectory
K‘ — Tower of the Corbius.
L — Knights’ hall.
M — Chapel.
N — Hall of the Officers and of the Government.
P — Battlements of the Châtelet.
Q — Court yard of the Merveille.
R — Staircase leading from the court of the Merveille to the terrace S.
S — Terrace of the Apse.
T — Courtyard of the church.
U — Fortified bridge joining the lower church to the abbatial dwelling
V — Abbatial dwelling.
X — Lodgings of the Abbey.
Y — Cisterns (XVth century).
Y‘ — Cisterns (XVIth century).
Z — Staircase leading from the underground to the higher church.
Z‘ — Solid rock.