Guadalquivir Marshes

The Guadalquivir Marshes (in lang es or simply Las Marismas) are a natural region of marshy lowlands on the lower Guadalquivir River. The Las Marismas zone forms a large part of the province of Huelva, province of Seville and province of Cádiz in Andalucia, Spain. The area includes parts of the municipalities of Isla Mayor, Los Palacios y Villafranca, La Puebla del Río, Utrera, Las Cabezas de San Juan and Lebrija. Rice farming in this area produces 40% of Spain's national crop. Some areas are protected for wildlife and habitat, including dunes.

Approximately two millennia ago the wetlands comprised a large lagoon and estuary, known as Lacus Ligustinus in Latin, leading to the Guadalquivir River mouth with some sand bars to the South. Over time the lake silted up, gradually transforming into marshland. This silt has formed into a barrier of dunes extending approximately along the coast, known as Arenas Gordas (English: "the fat sands"). In the early 21st century, the Guadalquivir wetland region's main economic activity is agriculture, specialising in the cultivation of rice. An area of about 400 km2 is devoted to rice farming. It has an annual output of about 310,000 metric tonnes, equating to approximately 40% of Spain's rice production.

The wetland zone acts as a buffer zone between the human settlements of the Guadalquivir region and Doñana National Park, a protected area of marshland, streams, and sand dunes. The National Park was established in 1969 as a nature reserve when the World Wildlife Fund joined forces with the Spanish Government to purchase a substantial part of the local wetlands in order to preserve them.

The Las Marismas area is home to a large number of wildlife species. Commonly seen terrestrial animals include deer, lynx, and wild boars. Notable avian species include vultures, flamingos, herons, spoonbills, and ducks. The rare Spanish imperial eagle lives here, whose population is considered vulnerable by the International Union for Conservation of Nature.