It is understood from the findings, which are obtained from the archaeological excavations, made on the tumulus in Çayönü that first settlement started around Diyarbakır in the Neolithic period( B.C. 7250-B.C. 6750). The first settlement in Diyarbakır city is in İçkale location in B.c. 2000 and it Diyarbakır city is in İçkale location in B.C. 2000 and it corresponds to Hurrians period. Mitannians dominate the period by beginning from B.C. 1500. Name of the city is Amidi in Assyrian sources dated B.C. 1300. This name changes and takes the shape of Amid in the course of time. Region is ruled firstly by Hittites by beginning from B.C. 1380 and then Assyrians, Urartians, Persians, Alexander, the Great, Seleucias, Partians, Romans in B.C. 69. After Roman Empire is divided into two pieces in 395, Diyarbakır remains within boundaries of Eastern Roman Empire. City is ruled by Arabians in 639, Seljuks in 1085, and then respectively İnaloğulları, Nisanoğulları, Artuqids, Anatolian Seljuks, Timur Empire, Karakoyunlular, Akkoyunlular and finally Ottomans in 1515. The important structure of the city is Diyarbakır Castle, composed of Citadel and Bailey. There are four gates in the citade, Fetih, Gate and Oğrun Gate are opened outside the city, Saray Gate and Küpeli Gate are opened into Bailey, which is the city center. Bailey Walls, which are also including Citadel, are in the length of 5,5 km and it has 82 bastions and four main gates, opening out of wall in the four directions. Dağ Gate is opened to the north, Urfa Gate is opened to the south, Yeni Gate is opened to the east. Among the bastions, located on the walls Ulubeden, Yedikardeş and Keçi Bastions are the works of Artuqids. There are many epigraphs, beloning to various periods, on Diyarbakır Walls. Diyarbakır Walls are almost an Epigraph Museum with these rich epigraphs. These epigraphs, bringin light to the history of Diyarbakir, belong to Roman, Byzantine, Abbasid, Seljuk, Artuqid, Ayyubid, Akkoyunlu and Ottoman periods and is in Greek, Latin, Persian and Arabic language. There are many old structures in Diyarbakır, having a long historical past. We can list some of other important architectural structures in the city as follows. When Diyarbakır is captured by Arabians in 639, St. Tomas cathedral,located here, is turned into the mosque and called Ulu Mosque. Zinciriye Madrasah is constructed in the southern-west of Ulu Mosque in 1199, Mesudiye Madrasah is constructed in its northern side in 1224. Iskender Pasha Mosque, constructed between 1551-1563, Safa Mosque, constructed in 1532, Kara Mosque, constructed by Kara Mustafa Pasha between 1644-1650 years, Kasım Padishah Mosque, constructed in 1500, Kurşunlu Mosque, constructed by the order of Bıyıklı Mehmet Pasha in 1522, Behram Pasha Mosque, constructed in 1572, Hüsrev Pasha Mosque, constructed between 1522-1528, Melik Ahmet Pasha Mosque constructed in 1587-1591, Prophet Mosque, constructed in 15th century and also Deliler Hostelry, Hasan Pasha Hostelry, Çift Hosrelry, Melik Ahmet Pasha Bath, Kadı Bath, Diyarbakır Houses and The Virgin Mary Church (Syrian), belonging to 3rd Century, St. George Church and Dicle Bridge, located on Dicle River, are some of the other important old structures in the city. Archeological Museum, in which archaeological and local ethnographic works, belonging to various periods, are exhibited, Cahit Sıtkı Tarancı House, Ziya Gökalp Museum and Command Atatürk Museum are the other places, which are required to be visited in Diyarbakır.