Argentina Argentina is a South American country with a population of thirty one million people. Argentina's capital is Buenos Aires, which is one of the largest cities in South America. Buenos Aires is situated on the coast of Argentina, which makes Buenos Aires a major trade route in Argentina and in South America. Argentina's national language is Spanish and the major religion is Roman Catholicism. Argentina is a country with much natural beauty. It has miles of beautiful beaches and is also surrounded by the majestic Andes mountains. The Andes mountains are among the highest mountains in the world. Argentina's tallest mountain is the Cerro Aconcagua. This mountain reaches an amazing height