Eski Kahta, also known as Kocahisar, is overlooked by castle ruins. Although there was once a palace here, built at the same time as the Commagene capital of Arsameia on the other side of the ravine, what you see today is the ruins of a 13th-century Mamluk castle, Yeni Kale (New Fortress). There are some Arabic inscriptions above the main and only gateway. You can climb up to look at the castle, but make sure you’re wearing appropriate shoes and watch your step.