Inner castle, divided from the city by an arc shaped wall on the northeast of the area covered by the walls, is in a way miniature of the Outer Castle with the walls surrounding it. Information on the resources about its construction date has a common view being built during Hurris Era. The surrounding of the Inner castle, dating back to Hurris, was surrounded by outer walls in 349 during Byzantine Era. Administration center of the city, Inner castle, has taken its final condition after getting under Ottoman Administration, after going through important changes during Artuklus Administration. Inner Castle has four doors in total: Palace, Ogrun, Kupeli, and Fetih. The doors of Fetih and Ogrun to opens to outside while the doors of palace and Kupeli opens to city. Each of the 16 dungeons of the Inner Castle has different functions. Dungeons, used in many functions such as gun ammo depot, grain and food depot, prison, military equipment depose, has undergone through many reparations during the Artuklus and Ottoman eras. Our cultural heritages will be tried to keep away from various risks by restoring with the Inner Castle Project carried out by Culture and Tourism Ministry and Diyarbakir City Governorship. With the completion of this project, our immovable cultural heritages will be functioned as in tourism area and will be kept away from risks such as ruining and collapse. There are, Artuklus Palace, Hz. Süleyman Mosque and 27 Companions Tomb, Saint George Church, The Lion Fountain, Artuklus Arch as well as public structures such as: Gendarme Building, Former Prison, Corps Building, Courthouse A and Courthouse B Buildings, Commander Atatürk Museum in the Inner Castle, which used to be city’s administration center in the history. His Holiness Suleyman Mosque and its surrounding will be kept away from the risks by restoring it without losing its unique structure within Urban Transformation Project carried out by Diyarbakir Metropolitian Municipality and Toki.