Final answer:
Buenos Aires is the city where the River Plate and Boca Juniors soccer teams are based, renowned for their intense rivalry known as the Superclásico.
Step-by-step explanation:
The city that is home to the iconic soccer clubs River Plate and Boca Juniors is Buenos Aires. These two teams are not only central to the city's sporting culture but are also famous for one of the most intense rivalries in the world of football, known as the Superclásico. Buenos Aires exudes a rich soccer history alongside its cultural and historical significance, as it was also a pivotal port during the eighteenth century in the Spanish Viceroyalty of Río de la Plata. This viceroyalty included the regions of modern-day Argentina, Bolivia, Paraguay, and Uruguay, highlighting Buenos Aires as a major outlet for commodities from these areas, as well as a hub for trade and contraband. The economic activities greatly benefited the area's inhabitants, known as Porteños.