The Lake Meligkou better known as Lake Moustou is situated southeast of Astros on the left side of road that goes to the village Neohori. Actually, it is a wetland system consisting of two lakes, Lake Moustos and a smaller, Lake Cherronissos. . It is located in the center of the bay of Astros, behind the sandy beach. The lake Moustos has a maximum depth 5 meters and communicates with the sea by two artificial channels – ditches. The Cherronissos Lake is formed by the waters of the spring that flows from the edge of the hill to the east and goes directly into the sea. The lake has many spas and many visitors swim close to the source.
The Lake Moustos is the most important wetland in the eastern Peloponnese, with priceless value for the ecological balance. It is the only place in the area that presents a gateway for the migratory birds. For this reason the area is protected and it belongs to the network of Natura 2000. The predominant vegetation consists of dunes, salt marshes and reed beds, while the interesting wildlife of the lake includes fish, reptiles, amphibians and a wide variety of birds. Moorhens, mallards, herons, swan and coots spend winter at this area while the coastline is inhabited by Caretta caretta turtles.