What makes Istanbul special and unique, is not its beauty, but the memories, the good and the bad of people who once lived there and were forced to leave for different reasons. This is something that people could realize as soon as they visit Istanbul and talk to the remaining minority populations who have faced bigotry, prejudice and persecution. Those have kept alive the real meaning of this metropolis. It is the multicultural and cosmopolitan character and especially the religious pluralism and diversity which still manages somehow to survive and characterizes the city and life in it, making it unique and offering a perfect symbolism since Turkey and especially Istanbul has become a significant mediator between the West and the East. Even though the figures have been dramatically changed and decreased, the city has retained some of its multicultural character, and still hosts some of the most important religious institutions. This is the main theme of this thesis, the history, the problems and the panorama of the life in the multicultural Istanbul. It is an overall view on different areas where population from different religious and cultural backgrounds co-existed for years and have a great historic meaning. The mahalles that will be examined in this study are those of Fener, Balat, and Ortakoy from the European side and Kuzguncuk from the Asian one. This thesis will try to highlight the main events which led to the alienation and the shrinkage of the religious populations in Istanbul, and will present a report on the current situation and projects which promote the religious diversity and aim to restore, partly, the glory of the multicultural past. Why nationalism prevailed and how did its predominance affect the multicultural Istanbul? What is the current situation in the neighborhoods which used to or still host populations from different religious backgrounds, and how do the recent cultural initiatives aim to bridge the gap that hatred and policies created?