The "Iron Gate 1" hydropower and navigation system, a complex, multi-purpose structure, is located on the 943rd kilometer of the Danube River, from the confluence of the Danube and the Black Sea.
Construction began on September 7, 1964, and the last damming of the Danube was completed in 1969. HENS "Iron Gate 1" was completed in 1972.
Serbia and Romania share one half of the symmetrical facility, consisting of an approximately 1,280-meter-long spillway dam, 14 25-meter-wide spillway bays, two two-stage ship locks with conning towers, and two machine halls housing six hydraulic units. The annual production of the entire hydropower plant is approximately 12.5 billion kWh of electricity.
Two-stage ship locks are among the largest of their kind in the world, with an annual capacity of 90 million tons of cargo. They consist of an upstream and downstream chamber length of 310 m and a width of 34 m. The height difference between the chambers is 30 m. "Iron Gate I" is also the border crossing between Serbia and Romania