This is a block removed from the Yeni area, but I store the picture(s) here for the time being. It is the central post office.

From the Wikipedia: The Istanbul Grand Post Office, aka Istanbul Main Post Office, (Turkish: Büyük Postane) is an office building for postal services located at Sirkeci quarter of Fatih district in Istanbul, Turkey. It was designed by architect Vedat Tek in First Turkish National architectural style and was constructed between 1905 and 1909. The four-story building houses a post office, the Sirkeci Post Office (Turkish: Sirkeci PTT Merkezi), office space for regional administration and also since 2000 the Istanbul Postal Museum (Turkish: PTT İstanbul Müzesi). It is Turkey's largest post office building.