Lake Butkovsko or Lake Kerkini is a lake in Aegean Macedonia, Greece, part of the Aegean Lakes group. The lake is famous for its rich flora and fauna and is one of the four best places to watch about 300 rare and protected bird species that live and multiply in it. It is a nature reserve and is part of Natura 2000.
It is situated between the Belasitsa (Kerkini) and Krusha (Krussia Ori) mountains in the northwestern part of the Serres.The wetland includes 25 km from the Struma River, 10 km from the Butkovska River (Kerkinitis) and many canals and smaller streams.At Lake Kerkini you can see animals that you usually visit your zoo – Flamingo, Dalmatian Pelican, Cormorant, Swan, Eagle, Falcon.
About 100 years ago, there were only a few small swamps and puddles near the bed of the Struma River. When dams are built to protect the floods of nearby villages, and to irrigate the Serres, it appears that many artificial birds are lying around the artificial lake and, instead of disturbing the natural balance, the man has contributed to it.