This protected nature reserve, extending through more than 250,000 acres, is located within the provinces of Huelva, Sevilla and Cádiz. It is the most important wetland in Europe, since the Guadalquivir river flows into it. Its large marshland area is the perfect habitat for numerous aquatic birds. Considered the largest ecological reserve in Europe, this paradise for multiple animal and vegetal species was declared a World Heritage Site by the UNESCO in 1984.