The most ancient part of the palace is the Tour de Trouillas, at the north-east angle, an immense mass which towers above all the other works and formed the Keep. The Pope’s apartments in the time of Urban V. were on the first floor of the buildings surrounding the _Cour d’honneur_. From the landing of the great staircase, which gave access to the principal apartments, passages were carried round the building in the thickness of the wall next the courtyard. These were carefully constructed and finished with pointed and groined vaults. They communicated with the various rooms, and also with several staircases which connected the different floors, and led to the defences on the roof. The apartments of the south court were also joined to those of the north court by these passages. The great kitchen was situated on the first floor of the building next the keep. It has a high pyramidal vault, which gives it a mysterious look, and perhaps led to its being long regarded as the chamber of torture and hall of execution of the Inquisitors. The banqueting hall was in the north court, near the kitchen and the keep. The smaller tower (M) in the centre of the east flank (now called the Salle de la Justice) contains in two floors some admirable paintings of the fourteenth and fifteenth centuries, which are in a fair state of preservation. The entire building is of the most massive masonry--the whole of the basement being vaulted and constructed so as to defy destruction. Commencing with the great keep at the north-east angle, and proceeding round the palace by the west, south, and east, the towers occur in the following order:--north-east--Tour de Trouillas; north-west--Tour de la Gache, followed by the Tour de St Jean, Tour de St Laurent, Tour de la Cloche, Tour des Anges, Tour d’Estrapade. One circumstance specially noticeable about the design of the palace of the Popes is the entire absence of effort after symmetry in the elevations, such as is generally aimed at in the case of the large palaces or halls of the late Gothic and Renaissance periods. Here the various blocks of building are simply placed where they are required, and the different levels and irregularities of the ground are made available in the most natural and convenient manner, with the result that the effect is delightfully varied and impressive from every point of view, and at every turning.[A] The rock on the north side is almost perpendicular, but here also the access had a defence called the Tour St Martin, which is now removed. From this point slopes led down to the gate of the châtelet which protected the bridge over the Rhone.