Donau-Schwarzmeer-Kanal
Although the idea of building a navigable canal between the Danube and the Black Sea is old, the first concrete attempt was made between 1949-1953, 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 thousand. The construction works of the Danube–Black Sea Canal were to be resumed 20 years later, in different conditions.