Answer:
It was the largest city during the Spanish Empire, the largest city in Hispania also during the last part of the Roman period. Seville had the monopoly in colonial trade during the Habsburg dynasty along with Cádiz, it was the headquarters of the Casa de Contratación which controlled Atlantic trade and the exploration of the Americas for centuries. Now the Casa de Contratación has become the archives of the Americas, the place where all the documents of the Spanish colonial empire are stored (maps, letters decrees, contacts…). All the history of the Spanish colonies is stored in the building of the former Casa de Contratación. Seville is also the place where Colombus’ remains are, his tomb is in Seville's Cathedral.
Right outside Seville in the town of Santiponce there are ruins from the Roman city of Italica. The amphitheatre of that town is where the Game of Thrones craddle of the dragons outside King's Landing is set. The place where Cersei meets with Daenerys or where they choose Bran as king. That town is also the birthplace and home of two Hispanic emperors, emperor Trajan and emperor Hadrian were born and grew up in that town.
Seville was one of the largest cities of the Muslim period as well and it has plenty of Moorish architecture like the Giralda Tower or the Gold Tower (where the gold in the city was stored), or the Alcázar (Seville's Moorish palace that was expanded by Castile during the Renaissance). The Alcázar of Seville is actually also another Game of Thrones setting, it is the setting of the Water Gardens of Dorne.
Explanation:
The dressing is traditional too, boys wear that charcateristic Spanish hat and suit and girls wear the same type of colourful spotted dresses with the peineta or flower in the hair, some go in carriages or horses. A friend of mine from Málaga goes every year to Seville for the fair
