Lake Coghinas covers about 18 square kilometres and has a capacity of approximately 250 million cubic metres. With a maximum depth of 50 metres, it separates the provinces of Olbia-Tempio and Sassari on the western border.
The fauna is comprised of greylag geese, northern lapwings, European golden plovers, and an important nesting colony of black-crowned night herons (i.e., nocturnal herons).