Hi! There's 7 different areas along the visitor route:
- The lower level room
- The quatrefoil room
- The south belfry (landing) and a very small section of the Gallery of Chimera
- The summit of the south bell tower
- The south belfry (inside) and the bells of the south tower
- The terrace between the north tower and south tower
- The north belfry
The visitor route is designed that each of these 7 areas have to be visited in this sequential order, and you can't go backwards.
However, if you don't want to climb to the top/the summit of the south bell tower, you can skip this area. Once you reach the south belfry (landing), you can tell the staff member who's there that you don't want to visit the summit and they will direct you inside the south belfry to continue the visitor route.