I'm going to keep this short and sweet. This is Tinto Verano, which means "summer red wine ". This is what most of the locals in Spain drink, rather than the more commonly known Sangria. The locals drink it because it's way easier to make and it's super cheap. You can adjust the drink to your taste. It's yummy, cold, and alcoholic, which is just perfect in this heat. It's also easy as 1, 2, 3.
Step One: Fill a glass with ice.
Step Two: Fill the glass about half way with some really cheap red wine. Use the stuff from the grocery store if you wanna rock it like a Spaniard.
Step Three: Fill the glass the rest of the way with some carbonated lemonade. I got mine at the local grocery store.
Step Four: Drink. Repeat, if necessary.