The Danube Road

In the park of the Fürstenberg palace there is a stone basin of clear water with an inscription saying the Danube begins there. It is not quite true: the river is born a kilometre and a half downstream, where the Brigach and the Breg meet. The two towns have argued for centuries over which is the real source. Either way, here you cross the water in one stride.

Three rivers meet at a single point: the Danube, the Inn and the Ilz. The Inn carries more water than the Danube and comes from further away, so hydrologically speaking it is the Inn that flows on from Passau. You can see three colours side by side: alpine green from the Inn, brown from the Danube, black from the Ilz.

Between Melk and Krems the river cuts a narrow valley with vine terraces on both banks, inscribed on the UNESCO list. Melk Abbey stands above the water like a yellow ship. At Dürnstein, in the ruin on the rock, Richard the Lionheart was held prisoner in 1192 on his way back from crusade.

Vienna has rearranged the Danube twice. First in the nineteenth century, straightening it so it would stop flooding the city. Then in the 1970s, digging a second parallel channel — and the spoil became the Donauinsel, twenty-one kilometres of artificial island that is now the city's beach.

The castle stands on its rock above the water, and ten kilometres upstream, at Devín, the Morava joins the Danube. For forty years that confluence was the Iron Curtain itself: Austria lay on the far bank, and this one was mined and patrolled. Today it is a park.

It is the only city on this route built on the idea of having a river: Buda on the hills, Pest on the plain, and seven bridges holding them together. To the north, at Visegrád, the Danube turns through almost a right angle and changes direction from east to south — the Danube Bend.

From here down, the Danube becomes a border. Vukovar was besieged for eighty-seven days in 1991 and almost entirely destroyed. The water tower, riddled with shell holes, was deliberately left that way and stabilised only enough to keep standing. The town has been rebuilt around it. It is not a sad place; it is a place that decided not to pretend.

Here the river narrows from a kilometre wide to a hundred and fifty metres and enters walls of limestone. On the Romanian bank is the face of Decebalus, fifty-five metres high, carved between 1994 and 2004 and the largest rock relief in Europe. Opposite, on the Serbian side, is the Tabula Traiana of the year 100. And beneath the water lies Ada Kaleh, the Turkish island drowned in 1970 when the dam was built.