Built in the early 17th century, this Catholic church is the oldest still-functioning Christian house of worship in the city. Its survival during the 1922 fire, which razed all neighbouring buildings to the ground, was nothing short of miraculous. Inside, the walls are covered in frescoes that were restored and added to in the 19th century by local architect Raymond Charles Père, who depicted himself in the fresco of St Polycarp's martyrdom (he's the mustachioed chap with the bound hands).
The church is named in honour of the city's patron saint, who was converted to Christianity by St John the Evangelist and became Bishop of Smyrna. He was burned at the stake by the Romans in AD 155 after refusing to renounce Christ and his feast day is observed on 26 January.
Ring the white door on Necati Bey Bulvarı 2 to gain entrance.