Koca Mustafa Paşa Camii (Sümbül Efendi Camii)

The mosque of the complex that gave the Kocamustafapaşa quarter its name, also known as the Sümbül Efendi Mosque. The building, which dates from the Byzantine period, was converted into a mosque in 1486 by Koca Mustafa Paşa, grand vizier of Bayezid II. According to the TDV Encyclopedia of Islam, the Ottoman architect gave it a new axis at right angles to the old one, turning it into a wide mosque oriented north to south, and added two half domes and a five-domed portico. The decoration of the minaret base is considered unmatched in Istanbul. The courtyard holds a column-shaped fountain of 1737, tombs and the grave of the calligrapher Hafız Osman.