Conclusion: choose Madrid for museums, nightlife and a transport hub; choose Seville for romance, Moorish architecture and a slower pace. - Madrid: the Prado, Reina Sofía and Thyssen museums, non-stop tapas culture and easy day trips (Toledo, Segovia); hotels and dining run pricier. - Seville: the Moorish Alcázar, one of the world's largest cathedrals with La Giralda, the free Plaza de España and the birthplace of flamenco; cheaper and far more walkable. - The AVE high-speed train links the two in 2.5 hours — one of Europe's easiest two-city combos. - First-timers and solo travellers: Madrid; couples and slow travellers: Seville.