Çinili Mosque hides its whole reason for being behind plain grey walls. From the Üsküdar street it asks for nothing — a single dome, a modest porch, cut stone. Its name gives the secret away: çinili means "tiled." Kösem Sultan, who steered the Ottoman court from behind the throne for decades, had it built in 1640 as the heart of a small charitable complex on the hill above the harbour.
Step inside and the restraint falls away. Tiles in pale blue, turquoise, and green climb the walls nearly to the dome — tulips, hyacinths, and peonies looping over a white ground, among the last flowerings of classical Ottoman tile art. Small windows keep the light low, so the room glows rather than dazzles, the tiled mihrab deepest of all; even the marble minber carries a little tiled cone for a roof. Above the busy grain of the Üsküdar shore, the mosque stays quiet, prayed in mostly by the neighbourhood that took its name. It is still a working mosque, and one of the finest tiled rooms in Istanbul that few visitors ever reach.