Autonomous City of Buenos Aires (Ciudad Autónoma de Buenos Aires) is Argentina’s big, cosmopolitan capital city. Its center is the Plaza de Mayo, lined with stately 19th-century buildings including Casa Rosada, the iconic, balconied presidential palace. Other major attractions include Teatro Colón, a grand 1908 opera house with nearly 2,500 seats, and the modern MALBA museum, displaying Latin American art.