Chalcedon
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.
Saittae
Saittae was also the seat of a Byzantine Bishopric. Bishop Limenius signed the Chalcedon Creed while Bishop 
Amachius spoke at the Council of Chalcedon. Although an Islamic area now, Saittae remains a titular see of the Roman Catholic Church.