Try sangria#21 of 27 things to do in Madrid
Sangria is prepared from red (rarely white) wine, diluted with water, with the addition of fruits. Depending on the wine quality and variety of fruits, the taste of sangria changes and in each new restaurant you can try a completely different drink.
Due to the fact that the wine is diluted with water, sangria is great for those who want to cheer themselves up a little but do not have one over the eight. It refreshes in summer when they add ice in it, and warms in winter, when sangria becomes a hot drink with cinnamon, cloves and nutmeg.