The Romans left a strong mark on Diyarbakır—not only did they lay the foundations for its famous city walls, but they created the basic layout of the old town: a rough rectangle with two main streets that cross and connect the four gates that are found at each compass point. The walls were constructed by the Byzantine Emperor Constantius in the 4th century and various Arab and Turkish rulers restored and added to them over the centuries, until the local Artukid Turcoman emir al Malik al-Salih Mahmud gave them their current form in 1208. On the whole, the walls remain in good shape along their entire length; indeed, if you feel like a bit of an adventure, the best way to appreciate these great walls is to wander along the top. Of the original 72 towers, 67 are still standing, decorated with myriad inscriptions in the language of every conqueror and with Seljuk reliefs of animals and men; you can also explore their inner chambers and corridors. In 2015, the walls became a UNESO World Heritage sight, along with the surrounding Hevsel Gardens, the greenbelt between Diyarbakir and the Tigris River.