The Mosque of The Aghas of The Inner Palace (Enderûn Ağalar Câmii) Located adjacent to the Privy Room, the Mosque of the Aghas of the Inner Palace was built in the time of Sultan Mehmed II for use by the sultan, the white eunuchs, and the pupils of the Inner Palace school. As the palace’s oldest, largest, and most central mosque, it was placed diagonally to the courtyard because it had to face in the direction of the Kaaba in Mecca. Its interior is decorated with early 17th-century Iznik tiles as well as 18th-century tiles produced in the workshops established at the Palace of the Porphyrogenitus (Tekfur Sarayı). Currently, the Mosque of the Aghas of the Inner Palace is used as the Topkapı Palace Library. Among the many invaluable manuscripts found here are not only works in Ottoman Turkish, Arabic, and Persian, but also manuscripts written in Greek and in Slavic languages.