Port of Constanța in the context of Mihail Kogălniceanu International Airport

The Danube–Black Sea Canal (Romanian: Canalul Dunăre–Marea Neagră) is a navigable canal in Romania, which runs from Cernavodă on the Danube river, via two branches, to Constanța and Năvodari on the Black Sea. Administered from Agigea, it is an important part of the waterway link between the North Sea and the Black Sea via the Rhine–Main–Danube Canal. The main branch of the canal, with a length of 64.4 km (40.0 mi), which connects the Port of Cernavodă with the Port of Constanța, was built in 1976–1984, while the northern branch, known as the Poarta Albă–Midia Năvodari Canal, with a length of 31.2 km (19.4 mi), connecting Poarta Albă and the Port of Midia, was built between 1983 and 1987.

Although the idea of building a navigable canal between the Danube and the Black Sea is old, the first concrete attempt was made between 1949 and 1953, when the communist authorities of the time used this opportunity to eliminate political opponents, so the canal became notorious as the site of labor camps, when at any given time, between 5,000 and 20,000 detainees, mostly political prisoners, worked on its excavation. The total number of prisoners used as labor force during this period is unknown, with the total number of deaths being estimated at several tens of thousands. The construction works of the Danube–Black Sea Canal were to be resumed 20 years later, in different conditions.