The Diyarbakir Castle and ramparts that have guarded the city for thousands of years - as if guarding a sacred relic by magnificently encircling the city - and the 8000-year-old Hevsel Gardens have been inducted into the UNESCO World Heritage List. The walls of Diyarbakir are 6 kilometers long and are the second largest city walls in the world after the Great Wall of China. It is located 100 meters above the valley of the Tigris River. Diyarbakir still bears the atmosphere of the Middle Ages with its almost intact and impressive walls that encircle the city, 10-12 meters high and 3-5 meters thick.