The Phanar Greek Orthodox College is the red-brick mass you see from across the Golden Horn, rising above Fener's tiled roofs with turreted corners and a great dome. It is much younger than the school inside it. You cannot go in: it is a school, closed to visitors, so you read it from the lanes below or from the far bank. The building was finished in the 1880s, paid for by the banker Georgios Zariphis, and its dome served as an observatory for astronomy lessons.
The school itself traces its line to 1454, the year after the Ottoman conquest, when the Patriarchate needed clergy and administrators it could train itself. In Greek it is the Megali tou Genous Scholi, the Great School of the Nation. Its graduates became the Phanariots, the Greek families of this hillside quarter. The Ecumenical Patriarchate still sits a few streets downhill. Behind the walls only a handful of students use rooms built for hundreds — the plainest measure of how far Istanbul's Greek community has shrunk.