GUARD ROOM — BELLE-CHAISE
After penetrating into the Barbican which protects the first gate and entering the Abbey by the fortified staircase under the Châtelet — an important point which we shall describe later on — we come to the Guard Room. This Guard Room is a part of the building called Belle-Chaise, erected by Richard Tustin, about 1250; at that time, the entrance to the Abbey was on the north side of this building on which opens a magnificent door which must be examined before passing through. It was closed by two panels, one of which was interior and the other exterior; on the lateral piers of this one, you can still see the iron collars surrounding the posts with which the leaves were turned, externally.
It was in this Guard Room that all comers deposited their arms before entering the monastery buildings unless exempted by special permission of the Prior of the Abbey. In the first years of the XV century, Pierre le Roy opened a door and a postern in the north front giving on the courtyard of the Merveille, a new entrance to the building which he commenced by joining the Merveille to the Châtelet; he built also the large chimney which stands opposite to the entrance door.
Having a simple design, The Guard Room is suited to its function. It is lighted on the east by a window surmounted by an oculus; in the second triforium on the south, a small door opens on a staircase, built in the thickness of the wall, which leads to one of the floors of the Perrine tower, to the door keepers’ room, and by a detour to the large hall above. In the third triforium on the south is the oblique passage leading by a flight of steps to the courtyard of the church.
ABBATIAL BUILDINGS
The courtyard of the church is formed: on the right by the beautiful bases of the chancel rebuilt in the second half of the XVth century by Guillaume d’Estouteville, and by the walls of the transept of the romanesque church and of the more recent constructions; on the left by the abbatial buildings, begun by Richard Tustin about 1250. They were continued, in the XIVth century by Nicolas le Vitrier and Geoffroy de Servon.
The lodgings of the Abbey then extended on the south of the church up to the west front of the south transept and were composed of several buildings one of which especially, the abbatial dwelling has a grand aspect. Pierre le Roy finished them about the end of the XIVth century.
At the northwest angle of the abbatial dwelling, towards the courtyard of the church, are to be seen the remnants of the arch of a bridge; this bridge joined the dwelling to the lower chapels of the chancel of the romanesque church; it was ruined at the same time as the romanesque chancel, in 1421.
A new bridge, the embattled parapet of which is sustained by machicolations with rich moldings, was built lower down in the same court by the cardinal d’Estouteville at the same time as the new chancel commenced in 1450. This open passage, on the level of the chapels of the lower church and of one of the floors of the abbatial dwelling, affords a passage, through the lower church, between the Buildings on the south and those of the Merveille on the North.
In the first years of the XVI century, Guillaume de Lamps, an abbot of the Mount gave orders for the erection of the building joining the south transept and running parallel with the south side of the nave. He pulled down the flights of steps leading from the Guard Room to the church and he ordered the large flight of steps to be made which still exists as well as the platform called the Saut-Gaultier, Avhich terminates it and on which opens the south Portal of the church. This abbot ordered also a wooden bridge to be erected, now worm-eaten, which joins the higher church to the abbatial buildings.
The construction of the building, joining the south collateral of the church and the transept, as well as the construction of the large flight of steps have greatly modified this part of the Abbey. Until the end of the XVth century, the staircase led from the courtyard of the church to the south lateral door. It established the necessary communications between the higher church and the west substructions where stood the Charnel-house or cemetery of the monks and in front of which was the mortuary chapel, so called of the thirty wax-tapers. —
This was under the Saut-Gaultier, were now maybe seen the large wheel — the entrance to it was on the east, at the foot of the south side-aisle. Some traces of the old arrangement, before the building of the large actual staircase, still exist in some parts of the underground vaults on the south.
From the beginning of the XVI century to our time, and after the fires of 1564 and 1594 which caused so much damage, the lodgings of the Abbey underwent important changes, especially as regards their roofs.
THE CHURCH
After ascending the large staircase leading to the platform of Saut-Gaultier and admiring the beautiful sight which you see from this eminence, you walk in the Basilica by the lateral Portal opened in the south collateral of the romanesque church.
Before visiting the higher church, you must first look at the large west platform from which you can perceive the sea making the horizon a splendid panorama and the considerable substructures which are the bases of the church and of the north, west, and south buildings, and which give an idea of the great difficulties which the first builders had to surmount to realize their monumental conceptions.

As we have seen in the historical notice, the church was begun in 1020 by Hildebert II, the sixth regular abbot of the Mount from 1017 to 1023, whom Richard II entrusted with the details of the works. We must attribute to this abbot the substructures of the romanesque church which, especially on the west side have gigantic proportions. This part of the Mount is one of the most interesting to be studied; it shows the greatness and the audacity of the work of the architect Hildebert. Instead of cutting into the top of the mount lin and principally in order not to diminish the majesty of the pedestal, he formed a vast plateau, the center of which is on the level of the highest part of the rock and the sides rest on the walls and on piers joined by vaults and make a basement of perfect firmness.
The transverse section shows the romanesque constructions surrounded by buildings that have been successively grouped around it at different times.

It shows on the north and south transepts, the crypts or lower chapels, which have not been cut in the roc, as it has been said, but constructed in the space between the declivity of the mountain and the plateau built by Hildebert.