Chalcedon
Chalcedon ( or ;
, sometimes transliterated as "Chalkedon") was an ancient maritime town of Bithynia, in Asia Minor. It was located almost directly opposite Byzantium, south of Scutari (modern Üsküdar) and it is now a district of the city of Istanbul named Kadıköy. The name "Chalcedon" is a variant of Calchedon, found on all the coins of the town as well as in manuscripts of Herodotus's "Histories", Xenophon's "Hellenica", Arrian's "Anabasis", and other works. Except for a tower, almost no above-ground vestiges of the ancient city survive in Kadıköy today; artifacts uncovered at Altıyol and other excavation sites are on display at the Istanbul Archaeological Museum.
Megara
In historical times, Megara was an early dependency of Corinth, in which capacity colonists from Megara founded Megara Hyblaea, a small "polis" north of Syracuse in Sicily. Megara then fought a war of independence with Corinth, and afterwards founded Chalcedon in 685 BC, as well as Byzantium (c. 667 BC).