Heraeum or Heraion (Ancient Greek: Ἥραιον), also known as Heraion Teichos (Ἡραῖον τεῖχος) was a Greek[1] city in ancient Thrace, located on the Propontis, a little to the east of Bisanthe.
Herodotus, Demosthenes, Harpokration, Stephanus of Byzantium and Suda mention the city.
In 352 BCE Phillip II besieged the city.
Athens decided to send a fleet of forty triremes and to levy sixty talents in order to help the city, but the fleet never set sail.
Only later a much smaller fleet of ten ships and money of five talents were sent.