We started our morning with a very informative cruise on the Duoro river.
A royal Portuguese charter of 10 September 1756 defined the production region for Port wine. It thus became the world’s first wine region to have a formal demarcation.
It is fascinating to see single rows of vineyards on tiny rock ledges, of which some vines are more than a hundred years old. Everything has to harvested by humans, since machines and animals can not navigate the steps.
https://en.m.wikipedia.org/wiki/Douro_DOC
