Aya Triada is the largest Greek Orthodox church in Istanbul, a domed grey-stone building with twin bell towers, set behind an iron gate and a small garden just off Taksim Square. Step through the gate and the roar of Taksim falls away. Inside, a marble iconostasis rises across the sanctuary, in a nave built to hold a thousand voices. The architect Vasilaki Ioannidis mixed styles freely: pointed Gothic windows, a sober face, and that dome.
When it was consecrated in 1880, the dome and the bells were the point. No church in Istanbul had been allowed a dome since 1453, and as Ottoman rules loosened the Greek community of Pera answered by building on this scale. Two four-storey belfries went up beside the narthex, and if you count the windows round the drum you will find twelve, one for each apostle. Mobs wrecked the church in the anti-Greek riots of September 1955, and it did not fully reopen until 2003. About a hundred and fifty parishioners keep it going now. On a quiet weekday you may share it with a caretaker and a few burning candles; on a feast day the bells ring out over İstiklal.