Which region of south America is most densely populated?

The most densely populated region of South America is the Southern Cone, which includes the countries of Argentina, Chile, and Uruguay. This region is home to over 40% of the population of South America, despite only occupying about 10% of the land area. The high population density of the Southern Cone is due to a number of factors, including favorable climate, fertile soils, and access to natural resources.