Stymfalia is a marshy lake in mountain area of Korinthia. It is located on a plateau at an altitude of 600 metres, between the mountains Κyllini and Oligyrtos. The water remains in the lake during winter and its extent is 3.5 km. Where there is always water, the depth is 2 / 2.5 meter on spring and on autumn it is half a meter.
Mythology:Lake Stymphalia is part of the 6th Labour of Hercules, and it was the place, where he fought against the Stymphalian Birds. Hercules managed to get them out of the dense vegetation of the lake with the help of the goddess Athena. Then, Hercules killed them with his arrows.