The Portul Constanța is the largest port on the Black Sea and the engine of the city's economy — a vast complex that runs for more than thirty kilometres of quay, handling oil, grain, containers and bulk minerals from the Danube hinterland and beyond. Since 2022 it has also become Europe's main alternative export route for Ukrainian grain, with thousands of barge tows running down the river to the sea.
The port itself is closed to casual visitors, but the long breakwater walls and the views from the southern end of the old town give a clear sense of the scale. A small port museum in the harbour authority building (open weekdays) covers the history from Roman Tomis through the Italian and Greek mercantile periods to the present. The container ships at anchor offshore, queueing for berths, are visible from the seafront on most clear days.