We flew from Barcelona to Porto, Portugal, as a base from which to explore the wines of the Douro Valley.  The physical beauty of the Valley, the proliferation of grapevines everywhere, and the quality of the wines were astonishing. I would rank the Douro as one of the most beautiful landscapes I have ever visited.

As a bonus, I enjoyed colorful Porto quite a bit, as well.  Good hotel, very good food (including a great vegetarian restaurant), a visit to the Taylor Fladgate Port winery across the river, and a fine place for walking and exploring — Porto exceeded my expectations.