Helical structure of rosettes page

[Mark Knowles]

When were those mountain passes made? What did they look like in medieval times? It might be that they already existed in this shape, but it's an important question to answer if you want to compare medieval artwork to modern photographs.

Vineyard terraces existed in the Medieval period in the lower alps. I haven't seen an illustration of precisely how they looked in Medieval times, but I can't see a reason why they should have looked very different. In some places the terraces form steep steps down to the river.
Clearly, determining what a given mountain pass looked like in medieval times can be more difficult.