The city's official seal includes a characteristic moment of the ancient Greek mythology. More specifically, the seal depicts Hercules fighting the river-god Achelous. According to the myth, Hercules fought against the river-god for the sake of Diianira, the princess of Calydon, which both of them wanted as a wife. Despite Achelous' transformations, Hercules managed to win the battle and got married to the princess. According to Strabo, the myth symbolises the struggle of ancient Aetolians to control the river's power with embankments, by which the river was confined to its bed and thus the area gained large tracts of land for cultivation.