Salisbury was one my favorites......featuring the tallest medieval spire in England. But what made it a must see forme was my Art History class, which described the bowed marble piers carrying the weight of that spire:
Look closely and you can see that the Piers bend slightly inward........Since marble deforms easily it was just able to adjust without collapsing (as crossing towers and walls often did during the middle ages).
A view of the west doors.
The Cathedral Close.