Diyarbakýr's single most conspicuous feature is its great circuit of basalt walls, probably dating from Roman times, although the present walls date from early Byzantine times (AD 330-500). At almost 6km in length these walls are said to be second in extent only to the Great Wall of China. They make a striking sight whether you're walking along the top or the bottom.
You can ascend the walls of the İç Kale to enjoy the fine views of the Tigris, flanked by a patchwork of market gardens, as it meanders 2km to 3km south to flow under the 11th-century On Gözlu Köprüsü (Ten-Eyed Bridge).