Rangeland in regions too dry to support a forest, but not dry enough to be a desert. Pampas are the fertile South American lowlands that include the Argentine provinces of Buenos Aires, La Pampa, Santa Fe, Entre Ríos and Córdoba, most of Uruguay, and the State of Rio Grande do Sul, in the southernmost end of Brazil covering more than . These vast plains are only interrupted by the low Ventana and Tandil hills near Bahía Blanca and Tandil (Argentina), with a height of and respectively. The climate is mild, with precipitation of to , more or less evenly distributed through
Argentina–Uruguay border former Eastern Band of the rest of the Viceroyalty of Rio de La Plata. Depending on the presence of this river, the border between Uruguay and Argentina was not disputed. From 1815 to 1816 the government of the United Kingdom of Portugal, Brazil and the Algarves (Brazil before independence) tried to annex the region of the current Uruguay to Brazil. This occurred with the Brazilian victory against Uruguay during the Battle of Tacuarembó in 1820. The region was called Province of Cisplatina of already independent Empire of Brazil. It was echoed by Uruguayan supported by troops from Argentina on 25