A near-perfect rectangular Roman fortress on the Black Sea coast, dating from the 1st or 2nd century AD and built to anchor the eastern Roman limes against Caucasian raids. The walls — about 200 by 245 metres — are largely intact, restored in Byzantine, Ottoman, and modern campaigns; the interior is now mostly grass, fruit trees, and the foundations of a Roman bathhouse.
A small site museum near the gate displays excavated finds — ceramics, coins, an unusual gold treasure unearthed in the 1970s. Allow about an hour. Bring water; there is no café inside the walls.