The Natural Park of El Fondo (Valencian: Parc Natural del Fondo, Spanish: Parque Natural de El Hondo) is located within the municipal boundaries of Elche and Crevillent both of which are within the comarca (district) of Baix Vinalopó in the south of the Valencian Community in the east of Spain. Both the rivers Vinalopó and Segura discharge into the lagoons that form this park.
This natural park is formed by a number of lagoons, of which the two largest are manmade and are called Levante, which has a surface area of 450 hectares and Poniente, with an area of 650 hectares. These two lagoons are fed by the waters of the river Segura. El Fondo and the Salinas of Santa Pola as well as the surrounding area formed part of the Albufera of Elche known to the Romans as "Senus Illicitanus".[3] The area of the park was infilled in the 17th century due to natural sedimentation and the placing of silt in order to create new areas for cultivation. At the same time the two largest lagoons were damned to supply water for irrigation.
Although the parks habitats are fairly homogeneous it is possible to distinguish two different types of environment relating to the depth and salinity of the water. The reservoirs contain fresher, less saline water with a high degree of eutrophication and therefore there is hardly any submerged vegetation although rushes and reeds are present in the deepest waters. The peripheral pools, are more saline and contain better quality water than the reservoirs and various species typical of salt marsh are present, such as sea lavender, shrubby seablight and glasswort.