Following a remarkable course from the Black Forest to the Black Sea, the Danube touches eight countries—and much of the history of Europe.
The Danube, the second longest river in Europe (after the Volga), meanders across the continent for 1,750 miles (2,800 kilometers). From its source in the cool depths of the Black Forest to its outlet on the sun-drenched shores of the Black Sea, the river varies dramatically in mood. Born as a mountain stream, along parts of its course it flows lazily across broad plains, while elsewhere it roars across rapids in deep, narrow gorges.
“Mother Danube” has long been an avenue for exploration, adventure, conquest, and commerce. Some of the first civilized tribes to reach Europe followed the Danube west from Asia, establishing agricultural settlements along the way. About seven centuries before the Christian Era, Greek sailors conducted a thriving trade with communities along the river’s lower course. Later, fleets of the Roman Empire patrolled its waters, and Roman legions built strongholds along its banks, including settlements on the sites of Vienna, Budapest, and Belgrade. Crusaders followed it east to the Holy Land, and Turks, traveling west, later captured the lower valley.
The Danube begins its long journey to the sea as an alpine stream formed by the merging of its two main headwaters, the Breg and Brigach, in Germany. Heading east into Austria, the river picks up speed as it flows through canyon like valleys hemmed in by wooded hills crowned with the ruins of medieval castles. Eventually the river reaches Vienna, where it flows through the city’s outskirts near the Vienna Woods. (This sector of the river inspired Johann Strauss’s famous Blue Danube waltz.)
The upper course of the Danube ends dramatically in a deep gorge upstream from Bratislava, Slovakia. Crossing the Little Hungarian Plain and then, beyond Budapest, the limitless expanse of the Great Hungarian Plain, the Danube slows down and becomes a flatland river somewhat similar to the Ohio or the Mississippi. With its current reduced to a placid flow, much of the silt carried down from the mountains settles to the bottom, clogging the channel with numerous islands. Although the middle course of the river is marshy and shallow in many places, this section of the Danube also receives the largest of its 300 tributaries, including the Drava, Tisza, and Sava.
Beyond Belgrade, the river enters the Danube cataracts. At its narrowest point here, known as the Iron Gate, the river boils between sheer rock walls 800 to 1,000 feet (250 to 300 meters) high and only 500 feet (150 meters) apart.. In some places the river reaches a depth of 175 feet (50 meters). Dams and canals make the gorge navigable, but boats moving against the swift current must be assisted by locomotives.
Below the cataracts the Danube changes character once again. Sluggish for much of its lower course, the river forms the boundary between Rumania and Bulgaria. To the north, in Rumania, it is bounded by a zone of lakes and marshes that give way to a broad lowland plain. To the south the banks rise steeply to the wide expanse of Bulgaria’s Danubian Plain.
About 50 miles (80 kilometers) from the Black Sea, the river begins to spread out into its delta, dividing into three major channels and multitudes of minor ones. The second largest delta in Europe, it covers an area of about 1,650 square miles (4,300 square kilometers).
This superb mosaic of land and water—including marshes, lagoons, islands, lakes, sandbars, and floating reedbeds—is the home of an almost unbelievable array of plants and wildlife. Best known for its birds (some 300 species have been sighted there), it also harbors 60 kinds of fish, herds of wild boar, and an astonishing assortment of other creatures. Famed as one of the most prolific wildlife sanctuaries in Europe, the Danube Delta attracts tourists and nature lovers from all around the world.