Dium or Dion was a city on the Acte or Akte (Ακτή) peninsula, the easternmost of the three peninsulas forming the ancient Chalcidice, on its northeastern coast, north of Olophyxus. Thucydides says that among the cities of the peninsula, Sane was colony of Andros, while Thyssus, Cleonae, Acrothoum, Olophyxus and Dium had a heterogeneous population of bilingual barbarians formed by a few Chalcidians and, the rest, Pelasgians, Bisaltians, Crestonians and Edoni. Strabo says that its primitive population was composed of Pelasgians from Lemnos. Pseudo Scylax writes that it was a Greek city. It was the closest city to the isthmus of the peninsula.