Sia Lagoon is a large lagoon located on the northern coast of Egypt. It is located in the Matrouh Governorate, near the Mediterranean Sea. The lagoon is approximately 4 km long and 1 km wide, and is a popular spot for bird watching and other nature-related activities. The lagoon is home to a variety of species of birds, including flamingos, pelicans, herons, and cormorants. It also supports a variety of fish species, such as mullet and sea bass. The lagoon is a popular spot for fishing and other water sports. The area is also home to a variety of plants, including salt-tolerant species.