Quick Answer: Buenos Aires, officially the Autonomous City of Buenos Aires, is the capital and largest city of Argentina. It is located on the southwest of the Río de la Plata. Buenos Aires is classified as an Alpha− global city, according to the GaWC 2024 ranking. The city proper has a population of 3.1 million and its urban area has a population of 16.7 million, making it the 21st most populous metropolitan area in the world. It is known for its preserved eclectic European architecture and rich cultural life. It is a multicultural city that is home to multiple ethnic and religious groups, contributing to its culture as well as to the dialect spoken in the city and in other parts of the country. Since the 19th century, the city, and the country in general, has been a major recipient of millions of immigrants from all over the world, making it a melting pot where many ethnic groups live together. Buenos Aires is considered one of the most diverse cities of the Americas.