Kadıköy known in classical antiquity and during the Roman and Byzantine eras as Chalcedon (Greek: Χαλκηδών), is a municipality and district of Istanbul Province, Turkey.Its area is 25 km2, and its population is 483,064 (2022). It is a large, populous, and cosmopolitan area in the Asian side of Istanbul, on the northern shore of the Sea of Marmara. It partially faces the...