Chalcedon 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 aboveground 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.The site of Chalcedon is located on a small peninsula on the north coast of the Sea of Marmara, near the mouth of the Bosphorus. A stream, called the Chalcis or Chalcedon in antiquity and now known as the Kurbağalıdere (Turkish: stream with frogs), flows into Fenerbahçe bay. There Greek colonists from Megara in Attica founded the settlement of Chalcedon in 685 BC, some seventeen years before Byzantium.