Heads up, awardtrail readers! If you've been dreaming of tapas and sunshine in Madrid, now might be the time to book. Delta (and sometimes its partner airlines) is offering round-trip flights to Madrid for as low as $638. Why should you care? Well, that's a pretty solid deal for a transatlantic flight these days, especially since it includes some perks that budget airlines often charge extra for. We're talking about being able to pick your seat ahead of time, bring a regular-sized carry-on, and even check a bag without additional fees. This deal is worth checking out if Madrid is on your radar and you value convenience and a little extra included baggage. Happy travels!