Laguna de Olomega consists of a lagoon, the largest body of natural fresh water in eastern El Salvador, and two small islets, in addition to a mangrove forest, swamps, and remains of a tropical dry forest. Its ecosystems support a diverse community of species, with over 100 recorded plant species, including 37 aquatic plants and vulnerable species such as the Spanish cedar (Cedrela odorata), big-leaf mahogany (Swietenia macrophylla) and Bravaisia integerrima, a tree of the Acanthus family which is listed as nationally endangered. In terms of fauna, 127 species of birds, 56 mammals, 17 reptiles, 13 fish and five amphibians have been recorded, including vulnerable species such as the American crocodile (Crocodylus acutus), and endangered species like the Geoffroy’s spider monkey (Ateles geoffroyi) and the Salvador stream frog (Ptychohyla salvadorensis). The Site is essential for nearby populations that depend on it for food, as well as flood control and water purification. Among the main threats are water pollution, overfishing, and changes in land use due to the presence of livestock, deforestation and forest fires.