Danube-Auen National Park

Listen first. Under the canopy of willow and poplar, the air is cool and damp, and it smells of wet bark and river mud. Somewhere ahead, water moves without hurry. A woodpecker knocks, stops, and knocks again. The ground under your feet is soft, almost springy, because this soil was laid down by floods. You are standing in a forest that belongs to a river. Every part of this landscape exists because the Danube rises, spreads out, and then pulls back again.

This is Danube-Auen National Park, a long green ribbon of floodplain forest between Vienna and the Slovak border. The word "Au" in German means a river meadow or floodplain wood. The park runs for roughly thirty-eight kilometres along the river. At its widest it is only a few kilometres across. It crosses two regions: part of it lies inside the city limits of Vienna, in the area called the Lobau, and the larger part lies here in Lower Austria.

Here is the first thing most visitors miss. On this stretch, the Danube flows freely. There is no dam holding it back. Across much of Austria, the river has been turned into a chain of reservoirs by hydroelectric plants. Here it still behaves like a wild river. Its level can rise by several metres after heavy rain or snowmelt in the Alps. Then it floods the side channels, fills the hollows, and moves gravel, sand, and fallen trees to new places.

That constant change is the engine of the whole park. A gravel bank that is dry this summer may be underwater next spring. An old side arm may silt up and become a pond. A new channel may open where there was forest. Scientists call this kind of landscape dynamic, and it is now very rare in Central Europe. Most of the great floodplains of the continent were drained, dammed, or farmed long ago. This one survived, partly by luck and partly by a fight.

That fight is the second surprise. In the early 1980s, the Austrian government planned a large hydroelectric power station near the town of Hainburg, at the eastern end of today's park. Construction would have flooded and cleared much of this forest. In December 1984, as the machines arrived, thousands of people walked into the snowy woods and refused to leave. Students, scientists, families, and pensioners camped among the trees through the bitter winter weeks.

The occupation of the Hainburger Au became a turning point in Austrian public life. Police were sent in, and the clashes shocked the country. The government stopped the work, and the power station was never built. The protest helped give birth to the modern environmental movement in Austria. A few years later, the idea of protecting this floodplain for good gained broad support. In 1996, Danube-Auen National Park was officially founded, and it is recognised under international standards for protected areas.

So when you walk these paths, you are walking through a place that ordinary citizens defended with their bodies in the cold. Keep that in mind as you look around. The old trees here are not decoration. Many of them are still standing because people sat beneath them and said no.

Now look at the forest itself. Near the water, you will find soft woods: willows and poplars that tolerate long floods and grow fast. Their roots hold the banks, and their branches often hang low over the side channels. Further from the river, on slightly higher ground, the hard woods take over. Oak, ash, and elm grow here, because they need drier feet. The difference in height may be only a metre or two, yet you can see the change in the trees.

The animal life follows the water. Watch the side channels for a flash of bright blue just above the surface. That is the kingfisher, a small bird that dives for fish. Look for tree trunks gnawed into a pencil point near the bank. Beavers did that. They disappeared from Austria in the nineteenth century, and they returned to this area after reintroduction in the 1970s. Today their dams and their chewed stumps are common sights along the quieter channels.

Other residents are harder to spot. The European pond turtle lives here, one of the few places in Austria where this shy reptile still breeds in the wild. On sunny days it rests on logs, and it slips into the water at the first sound of footsteps. High above the river, you may be lucky enough to see a white-tailed eagle, a very large bird of prey with broad wings and a pale tail. In winter, many waterbirds gather on the open water.

The river is also part of the visitor experience. You can join a guided boat or canoe tour through the side arms, where the forest closes in on both sides. On land, a network of marked paths leads through the woods, across meadows, and out to gravel banks on the main river. The National Park Center in the castle at Orth an der Donau is a good place to start. It explains the floodplain clearly, and it has an underwater observation area.

The park also sits in a landscape full of other stories. Downstream, the Danube passes the old town of Hainburg with its medieval walls. Nearby lie the remains of Carnuntum, once an important Roman city on the frontier of the empire. And just beyond the eastern edge of the park, the Morava River joins the Danube at the border with Slovakia. For two thousand years, people have traded, fought, and travelled along this water.

Before you move on, stand still for one more minute. Look at the colour of the water: green-brown, carrying silt from the Alps. Notice which way the light falls through the willows, and how the ground changes under your boots as you walk. Listen for the river, even when you cannot see it. This forest will look a little different the next time you come, because the Danube is still reshaping it... quietly, one flood at a time.