Lake Copais

A one-time island in the lake was modified in ancient times into a megalithic citadel, now called Gla.

[4] In 1865 a French company, Montferrier and Bonnair, signed a contract with the Greek government to drain the lake.

[8] Modern excavation has found enormous channels dug in the 14th century BC which drained water into the sea to the northeast;[9] Strabo mentions work being done on these channels by an engineer named Crates of Chalcis in the time of Alexander the Great.

[2] An incomplete tunnel with planned length of 2.2 km (1.4 mi) at Kephalari, close to the sinkholes, leading water rivers Cephissus and Melas to a small torrent leading eventually to the Euboean Gulf may also be a Bronze Age work;[2] however, currently there is no consensus about the matter and some researchers date the tunnel much later,[1] perhaps during the Hellenistic period.

[3] There was a legend that the lake came into being when the hero Heracles flooded the area by digging out a river, the Cephissus, which poured into the basin.

[11] Polyaenus explains that he did this because he was fighting the Minyans of Orchomenus: they were dangerous horseback fighters, and Heracles dug the lake in order to unhorse them.

[13] The travel writer Pausanias and the 5th century BC comic playwright Aristophanes record that in antiquity Lake Copais was known for its fish, especially the eels.