On entering by the west door a peculiarity will at once be noticed. About fifteen feet from the inner side of the west wall there is a rise of five steps which stretch right across the church from north to south. The floor to the east of these steps slopes imperceptibly upwards for eight bays, when a rise of three more steps is met with. On this higher level stands the altar, which is backed up by the rood screen. There is another step to be ascended to the level of the choir, and another to reach the space below the tower. Five steps lead from this into the presbytery; there is another step at the high altar rails, and four more lead up to the platform on which the high altar will stand. From the space below the tower one step leads up into the north aisle and two more into the north arm of the transept. From the level of the south choir aisle and south transept two steps lead up into the south aisle of the presbytery; from this aisle there is a rise of four steps into the aisle south of the Saint's Chapel, and from this into the chapel itself a rise of four more. So that the floor of this chapel is, with the exception of the high altar platform, which is one step higher, the highest in the whole church, or nineteen steps above the floor just inside the west door. From the aisle of the Saint's Chapel one step leads into the retro-choir, and two more into the Lady Chapel; hence the floor of the Lady Chapel is one step lower than that of the Saint's Chapel. If we take seven inches as the average height of a step, it would appear that the floor of the Lady Chapel is about ten feet higher than the floor at the west end of the nave. As we stand just inside the west door of the church we are struck by the length of ritual nave, about 200 feet, the flatness of the roofs, and the massiveness of the arcading dividing the nave from the aisles; for, though the four western bays on the north side and five on the south are Early English in date, there is none of that lightness and grace that we are accustomed to associate with work of this period, no detached shafts of Purbeck marble such as we see at Salisbury, no exquisitely carved capitals such as we meet with at Wells. William of Trumpington seems to have aimed at making his work harmonize with the Norman work that he left untouched; and when the rest of the main arcade on the south side was rebuilt in the next century, it was made to differ but little in general appearance and dimensions from Abbot William's.