Defterdar Mosque

The Defterdar Mosque, or the Defterdar Mahmut Efendi Mosque, is 16th century Ottoman mosque located in Eyüp, Istanbul, Turkey. It was commissioned by Nazlı [Mahmut Efendi] and built by architect Mimar Sinan in 1542. Instead of a crescent, this mosque has "ink pot and pen" on top of its dome, representing the profession of the founder of the mosque. The original pair was broken by a storm in 1997. Ten years later, on 30 May 2007, a new inkpot and a pen assembled on top of the dome of the mosque.