Eastern Transept Staircase                             -      N      - 
(-------------------------------------------------)     W <---(M)---> -
                                                        -      S      -

Attached to the eastern wall is a narrow staircase leading up to the
triforium gallery on the second floor.  A wooden handrail on the staircase
helps guide residences upward to the many features of the second floor. 
This room appears to be an intersection of the transept and the eastern
hallway that runs north and south.  Looking west you see the mighty crossing
square in which the east and west transept intersect.