We just returned from a 10-day stay in Porto, where we hired an amazing guide, named Daniel Ferreira, to take us through the Douro Valley (easily the highlight of our trip).
Daniel is a knowledgeable, engaging, intelligent young man, with a genuine passion for the beauty, history, and significance of his Douro Valley homeland. Although we hadn't met him prior to the tour (though we did communicate via email) Daniel immediately treated us like friends, not tourists. He tailored a perfect day for us, which included personal roundtrip transportation from/to our hotel in Porto, tasty meals (lunch and dinner), breathtaking photo ops, two local quintas, delicious wine tastings, and a leisurely one-hour river cruise... plus an abundance of laughter and fellowship.
If you want to forgo the "typical" Douro Valley tour in favor of a truly authentic and meaningful experience, then I highly recommend emailing Daniel ([email protected]) and/or visiting his homepage https://terradalma.com/).