Thirty five km from Serres, in the northwestern part of the prefecture, the artificial lake of Kerkini was created in 1932, when the dam at Lithotopos was built and the dikes made to the east and the west of it. It serves many purposes: prevention of floods, irrigation, and variety of biological species, educational, recreational, scientific. It is one of the few times when the human factor did not have a negative effect on nature, did not destroy the wonderful harmony and coexistence of the flora and fauna. Nowadays it has turned into a rare water reserve, which is protected by the International Convention Ramsar, so that any human intervention would be considered and controlled.

     The flora and fauna here are very rich. More than 300 kinds of birds have been recorded, which constitutes about 65% of the total number of birds that can be found in our country, many of which are rare or in danger of extinction. . This marvelous environment is the home of Dalmatian pelicans, Coemorans, Spoonbills, Ibises, Pygmy Cormorants, Flamingos, Imperial Eagles, Booted Eagles, herons etc. A large northern part of the lake is covered with water lilies in spring, which is the largest of its kind in Greece. In the northeastern part of the lake where the river Strymonas flows into it, there is a riverside forest, which is the main place for birds to feed and make their nests and a place where fish reproduce and grow. The forest-covered mountains surrounding the lake, Kerkini (Belles) and Mavrovouni (Krousia) are reflected in its waters. The villages situated near the lake are immersed in the green, too, their inhabitants are very proud of the lake, which they protect in every way they can and are trying to turn it into a tourist attraction by building various substructure works. The cow-buffaloes that live at the shores of the lake represent the typical local species of genetic variety.

     The lake can be visited either from the northern communities of Mondraki, Kerkini, or from the southern and eastern communities of Limnochori, Megalochori, Chrysochorafa and Lithotopos. 

     Nowadays, with the private travel and recreation facilities available in the area, it is easy to make a visit to the lake either to watch the birds fly, or to see the lotus-blooms, to enter the forest in the lake and to admire a beautiful sunset. Both the walkers and the cyclists also have opportunity to get acquainted with the area around the lake.

     The route from Lithotopos to Kerkini at the feet of the Krousia Mountain is of great tourist and construction interest.