Chalcedon was an ancient maritime town of Bithynia, in Asia Minor. It was located to the south of Chrysopolis and almost directly opposite Byzantium across the Bosporus strait, in Europe. At present,
The Church of St. Euphemia, which serves as the Greek Orthodox cathedral of the Metropolitan Diocese, was named after Saint Euphemia the All-praised, a virgin martyr who died in Chalcedon for her faith in 303 AD