One of the most beautiful places for hiking and wildlife observation in Northern Greece is located just 6 km from Edessa, in the wetland of Lake Agra - Vrytton - Nisioy. Known until recently as "Lake Agra" but renamed to include the three settlements that surround it, it was artificially created in 1953, to serve the Hydroelectric Power Station of PPC, on the bed of the river Edessaio (Voda). At the point, between the mountains Kaimaktsalan and Vermio and at an altitude of 470 meters, there was a pre-swamp (Tiavu).
The water of the lake in the first decades came from the nearby Vegoritida, but since 1990 it receives water from the surrounding springs and torrents. In the developed wetland there are large varieties of fauna and especially birds, with more than 250 species that live, reproduce or nest in the lake, some of which are characterized as rare. The water covers an area of about 7,000 acres.
The perimeter, the road that surrounds it with a diameter of about 18 km offers the possibility of observing the lake from all sides. The hiking trail, combined with the magical images of the colorful riparian vegetation and wetlands that host the water is unique. Lucky visitors will see the rare mute swans, which gave the name "swan lake" in the landscape but also silver pelicans, herons, marsh ducks, and black storks, in harmonious coexistence with the rest of the fauna and vegetation that covers the whole area. One visit may not be enough to enjoy everything that the Lake has to offer.