Zerzevan Castle is a historical structure and military settlement located between Diyarbakır and Mardin. It was used as a border garrison during the Roman Empire period. Considered one of the most important Eastern Roman works in Diyarbakır, the castle entered the World Heritage Tentative List in 2020. As a result of the excavations in the castle that started in 2014; 12 meters high, 1200 meters long wall ruins, 22 meters high watchtower, churches, palace, residences, rock tombs, baths, grain and weapon stores, and 54 water cisterns were unearthed. Zerzevan Castle is an important tourism center today.