Photo: GetYourGuideThe Douro is the reason many people come to Porto, and this best-selling day trip does the hard work for you, driving out through terraced vineyards to two quintas for tastings, adding a boat ride on the river and a regional lunch. It is a long but rewarding day. Wear layers for the valley mornings, sit on the left of the coach for the best views on the way out, and go easy at the first tasting.