Mesopotamia (literally, “land between rivers”) was the name the ancient Greeks gave to the region between the rivers Tigris and Euphrates, or modern-day Iraq. Argentina’s MESOPOTAMIA offers quite a different landscape, but it too lies between two great waterways, the Río Paraná and Río Uruguay, which merge just north of Buenos Aires to create the mighty Río de la Plata. The Paraná, which has its source in deepest Brazil, measures just over 4700km – making it the longest river in South America outside Amazonia – and forms much of Argentina’s frontier with Paraguay; the Uruguay, less mighty but impressive nonetheless, divides Argentina from its tiny eastern neighbour, also called Uruguay, and further upstream, from Brazil. The closest of the Litoral’s provinces to Buenos Aires is Entre Ríos, or “Between Rivers”: one of the country’s smallest provinces, it offers a soothing verdant landscape characterized by low hills – mostly little more than ripples – known locally as cuchillas. The province’s most impressive attraction is the Parque Nacional El Palmar, an enormous protected grove of dramatically tall yatay palms towering over the surrounding plains. The park is easily reached from Colón, the pick of a string of slow-paced riverside resorts running up the Río Uruguay along the eastern border of Entre Ríos; while one of Argentina’s liveliest carnivals, heavily influenced by Brazilian customs, is held at another river resort, Gualeguaychú, in the summer. North of Entre Ríos is the largely flat province of Corrientes, with an attractive provincial capital, Corrientes city, and the countless lagoons and wildlife treasures of Iberá at its centre.