The Pampas is a region in central Argentina bordered in the north by the Chaco region, in the northeast by the Mesopotamia region, in the east by the La Plata River (separating it from Uruguay), in the southeast by the Atlantic Ocean, in the south by the Patagonia region, in the west by the Cuyo region, and in the northwest by the Andean Northwest region.

Mesopotamia is a region in the northeast of Argentina bordered to the north by Paraguay, to the east by Brazil and Uruguay, to the south and west by the Pampas region, and in the northwest by the Chaco region.