This Master‘s thesis deals with the design of a building complex in Istanbul. This complex is called „Külliye“. A Külliye is a socio-religious foundation that basically belongs to a large mosque and is originally from Ottoman culture. The proposed property is located in the Ayvansaray Park on the Golden Horn, in Fatih, the historic peninsula and one of the oldest districts of Istanbul. The facilities at this Külliye include an education center with library, seminar rooms, lecture hall, etc., a health center, a hammam with accommodation, a café, function rooms and finally three prayer rooms - a mosque, a church and a synagogue.There is usually a mosque in a classic Külliye of Ottoman architecture, but in my project there will be two more prayer rooms. Because the goal of my work is to create a „place of peace“.