Su Staini saliu is a small pond of slightly brackish water that occupies an area of about 23 hectares, has a depth of almost 2 meters, and the bottom is composed of a substrate of impermeable inorganic origin so that with evaporation, especially in the summer period, the formation of layers of salt is favored.
The banks of the pond have partly retained the natural characteristics of marsh waters and are rich in tamarisk, rushes and coral grass.
In the spring and fall, thanks to the environmental conditions and the presence of ponds, various species are found including: ducks, waders, black-winged stilts, gulls, avocets, egrets and the pink flamingos.
Located in the countryside of Sestu, it is about 3 kilometers from the town and is easily reached by proceeding north along the S.P.4 to Ussana.