Church of St. Mary of Blachernae
Tucked near the Golden Horn, the Church of St. Mary of Blachernae marks one of the most sacred sites of Byzantine Constantinople. The original sanctuary here is said to have held the robe and relics of the Virgin Mary and was believed to protect the city itself. Rebuilt in 1867, the intimate church still shelters a holy spring (ayazma) where pilgrims come to draw its waters — a quiet, atmospheric start to the tour.