The Douro River Valley and wine region is huge. We sailed for most of three days and never stopped seeing terraced vineyards.
Here are some photos.

Vineyard Terraces used to all run with the elevation contour lines. Now with mechanization, they run any direction that maximizes the use of the land.

Crushing the grapes the old fashioned way. The larger wineries have machines to do this, but many mid to small sized wineries still do it this way.

Going thru the locks. The ships are built as wide and long as the locks will allow with about a foot of clearance on each side.

Slate and Schist rock formation. The slate cracks, either naturally or helped along with dynamite, and allows the water and roots of the grapevines to go to tremendous depths. The rain from the 9 wet months goes down through broken plates of slate and stores in intermediary layers of soil. Then during the dry summer the water is fed slowly up through the roots to the vines as much as a hundred feet above.