The Pampas, also known as the Pampas Plain, are fertile low grasslands located in southern South America. This vast natural region covers more than 1,200,000 km² (460,000 sq mi) and encompasses significant portions of several countries, including the Argentine provinces of Buenos Aires, La Pampa, Santa Fe, Entre Ríos, and Córdoba; all of Uruguay; and the southernmost state of Brazil, Rio Grande do Sul.
The landscape is characterized by expansive plains interrupted only by the low Ventana and Tandil hills near Bahía Blanca and Tandil in Argentina. These hills reach heights of 1,300 m (4,265 ft) and 500 m (1,640 ft), respectively. While naturally occurring, the ecoregion has been significantly altered by human activity, particularly through the introduction of livestock such as cattle, pigs, and sheep.