Lagoon Prokopos is between Marsh Lamia and Black Mountains. It occupies an area of 375 acres and its depth varies from 0.50 cm to 1.5m. It has a notable fauna such as ducks, herons, common coots and other birds. It is also used for fish production. It is protected by the Ramsar Convention and it’s most popular under the name Kalogrias Lagoon. It has a bird observatory and the lake connects with the sea through a narrow canal of 2.5km length, 6m width and 1.80m depth, where two small rivers flow into.