Diyarbakir is a field of mosques and Turkish people cluttered with medieval streets in renewed and old buildings. Sitting in sidewalk cafes the clouds breeze fast over head in the clear blue sky, whilst below the tea matches the air for heat but adjusts one’s own body to the climate, keeping a balance with nature and the heart of city. The gulls cry above the ports as boats set out in all directions on the highways of the water just as the street-trams roll off their list of destinations – Bakir is as Clockwork as Vienna. Diyarbakir still carries a medieval air with the encircling city walls. These black basalt walls are perfect examples of the military architecture of the Middle Ages. 
They are also very well known since they are the second largest (5.5 kms) and best preserved walls in the world after the famous Great Wall of China. Although there were Roman, and probably earlier walls here, the present walls date back to early Byzantine times.
There are sixteen keeps and five gates, each of which deserves seeing along with their inscriptions and relief. There are four main gates along the wall called as Dag Kapi, Urfa Kapi, Mardin Kapi and Yeni Kapi.