This historically mountainous part of the Danube proved un-navigable prior to the 19th century due to the rapids and whirlpools created by the Iron Gate gorges. There, between the lower Carpathian Mountains lying to the north and the Balkan Mountains to the south, the Danube river carves a passage through the rock, creating a series of four steep gorges. These gorges are known as the Iron Gate. The sight of these cliffs struck fear into the hearts of all sailors – even those who are seasoned navigators. Within the last of the four gorges is the Danube’s second Iron Gate: the Iron Gate Dam.
Apart from Orsova and a few very small towns which form tiny silver dots on the north shore of the river, the region west of the Iron Gate Dam is notably free of signs of human habitation. The square grids of vegetation created by agriculture are missing, as are sprawling silver cities. The lands on both sides of the river are protected. Djerdap National Park lines the south shore of the river in Serbia, and Portile de Fier National Park forms the Romanian shore in the north. Both parks protect the natural environment as well as significant cultural and historical sites ranging from Neolithic settlements to a medieval fortress.
The high riverbed rocks and the whirling rapids made the gorge valley an infamous passage for shipping. Near the actual “Iron Gates” strait the Prigrada rock was the most formidable obstacle until 1896. The river was widened considerably here and the water level was consequently lowered. Upstream, the Greben rock near the “Kazan” gorge was also a notorious spot for shipping.
In 1890 near the city of Orsova, rocks were cleared by explosion over a 1.2 mile stretch in order to create a deeper and wider channel. The same was done to a stretch of the Greben Mountains.
The results of these efforts were slightly disappointing. The currents in the channel still remained so strong that, until 1973, ships had to be dragged upstream by locomotive. Avoiding the Iron Gates therefore remained an obstacle, but not an insurmountable peril.
The construction of the joint Romanian-Yugoslavian mega project that would finally tame the river commenced in 1964. In 1972 the Iron Gate I Dam was opened, followed by the Iron Gate II Dam in 1984.
The construction of these dams transformed the ecology of the Danube valley below Belgrade into that of a reservoir, and additionally caused a 35 meter rise in the water level of the river near the dam. The old Orșova, the Danube island of Ada Kaleh and at least five other villages, totaling a population of 17,000, had to make way. People were relocated and the settlements have been lost forever to the Danube.
The dam’s construction had a major impact on the local fauna and flora as well. That said, since the construction of the dam the surrounding lands have been declared national parks, with both nations protecting the wildlife, as well as the geomorphological, archaeological and historical artifacts that lie in the vicinity of the Iron Gates.
The isle of Ada Kaleh is probably the most evocative victim of the Iron Gate dam’s construction. A Turkish exclave, it had a mosque and a thousand twisting alleys, and was known as a free port and smugglers nest. Many other ethnic groups lived there beside Turks.
The island was just downstream from Orșova. This made it a strategic location from a military perspective: the Austrians built a fort there in 1669 to defend it from the Turks, and that fort would remain a bone of contention between the two empires. In 1699 the island came under Turkish control, from 1716 to 1718 it was Austrian, after a four-month siege in 1738 it was Turkish again, followed by the Austrians reconquering it in 1789, only to have to yield it to the Turks in the following peace treaty.
Thereafter, the island lost its military importance. The 1878 Congress of Berlin forced the Ottoman Empire to retreat far into the south, but the island remained the property of the Turkish sultan, allegedly because it was forgotten to be mentioned in the treaty. In 1923, when the Ottoman monarchy had disappeared, the island was given to Romania in the Treaty of Lausanne. Before the construction of the Iron Gate Dam, the inhabitants of the island were given the choice of where to relocate. Most Ada Kaleh inhabitants emigrated to Turkey after the evacuation of the island. So sadly this quirky little island with all its history is now forever lost to the Danube.