Argentina is a vast country located in the southern part of South America. The eighth largest country in the world, it is the second largest country in South America after Brazil, and it's about one-third the size of the United States. Argentina is bordered by the Andes Mountains and Chile to the west. To the east of the Andes, the interior of the country is flat, fertile grassland called the Pampas. The eastern border of the country is the Atlantic Ocean. Bolivia is to the northwest and Paraguay is to the north. The high mountain spine of the Andes, called the Andes Cordillera, creates a natural 3,195-mile (5,141.9-kilometer) border with Chile. The country is divided into four regions: The Andes, the North, the Pampas, and Patagonia. The Pampas is the agricultural heartland.