Haydarpasa district, Kadikoy

In and around the famous Haydarpaşa railway station in Kadıköy on Istanbul's Asian side. The station was built in 1906 by German engineers, who established a small but now vanished community nearby. The building was severely damaged by fire in 2010 during restoration work and lost its roof and the fourth floor. There are plans to turn it into a hotel, so it is rumoured. 

Update, Dec. 2019: the roof was repaired in 2018-19, and it has not been turned into a hotel.