Europe's second-longest river and the most international river on Earth, flowing through or bordering ten countries.
Length
2,850 km
Source
Black Forest, Germany
Mouth
Black Sea (Romania/Ukraine delta)
Continent
Europe
Countries
10 countries, Germany to Ukraine
Did you know?
The Danube passes four national capitals — Vienna, Bratislava, Budapest and Belgrade — more than any other river.
Little-known fact
In the Iron Gates gorge the river carved a canyon so deep that a Roman road once had to be cut into the cliff face above the water.
Highlights
- Flows through ten countries
- Passes four capital cities
- Carved the dramatic Iron Gates gorge
Life in the Danube
The fish and animals, waterbirds and water plants — including some of the rarest — that this water supports.
Animals & fish
Beluga sturgeon
A giant armoured fish that can live over 100 years and yields the world’s most prized caviar.
Wels catfish
A monstrous European catfish that can top 2.5 m and has learned to beach itself to catch pigeons.
Eurasian otter
A sleek, playful hunter whose return to a river is a sign the water has run clean again.
Northern pike
A long, torpedo-shaped ambush predator that lurks among weeds across the cool rivers and lakes of the north.
Waterbirds
Common kingfisher
A dazzling blue-and-orange dart that plunges from a perch to spear fish in an instant.
Grey heron
A patient, statue-still angler that stalks the shallows of rivers and lakes across the Old World.
Mute swan
The great white swan of European waters, gliding in pairs that often mate for life.
Mallard
The familiar green-headed dabbling duck — ancestor of most domestic ducks — found on waters worldwide.
Water plants & reeds
Common reed
The tall, feathery grass that forms the vast reedbeds fringing rivers and lakes, sheltering countless birds.
Interactive · 3D journey
Journey of a river · source → sea
Every river runs the same great journey — from an icy mountain spring, down through gorges and looping meanders, to a wide delta where it meets the sea. Tap a stage to follow the water downstream.
Tip: hover to tilt the valley · tap a stage to float downstream
The Source
Every river begins high up — in a mountain spring, a melting glacier or a boggy upland. The water is cold, clear and fast, tumbling down the steepest ground of its whole journey.
Landforms here