A clerestory is the high windowed part of a wall above adjoining lower spaces. In Durham Cathedral, look past the main arcade and gallery to the upper windows. English Heritage describes these stacked levels in larger Norman churches.
Read the wall in layers from floor to roof instead of counting all its windows together. The entry belongs here because the position of an opening matters as much as its shape. Compare these high windows with the rose window at #5: one term describes location, the other a particular circular design.
Source: English Heritage · Photo: Oliver-Bonjoch · CC BY-SA 3.0. Resized/recompressed; image retains source license.
