It is not all blue because it also has green and brown tones, and its flow does’t carry only water, but also politics and memory. It is the mirror of the most beautiful buildings; it is border and arbiter between countries…The Danube has provided drinking water to half of Europe and has dragged hate, death, and musical notes on its way from the west to the east. With its 1770 miles, the imperial and unruly river is the second longest in Europe after the Volga, which is 620 miles longer.

The Danube springs from the Black Forest, near Donaueschingen, Germany, and ends at the Danube Delta in the Black Sea in Romania. The delta was declared a Biosphere Reserve by UNESCO in 1990 for being home to thousands of species of plants, birds, and fish. In its course, the river passes through some of the most beautiful cities in Central Europe, such as Regensburg, Passau and Ulm in Germany, and also touches on Austria, Slovakia, Hungary, Croatia, Serbia, Romania, Bulgaria, Moldova and Ukraine.

While one could navigate it all in one trip, there are glorious stretches that are worth a little vacation. For example, the place where the Danube curves along a narrow valley through the Carpathian Mountains, about 10 miles north of Budapest, Hungary, allows travelers to visit the charming villages of Szentendre, Visegrad and Esztergom.

1. Budapest; 2. Esztergom; 3. Vienna; 4. Danube Express.

On its way through Austria, the Danube offers some of the most beautiful scenery of its long journey, meandering through green valleys, near castles, medieval villages, and baroque abbeys. In Vienna, the capital, it is wonderful to watch the swans glide over its waters. In the city, the river divides into three branches: the New Danube, the Old Danube, and the Canal, which borders the old town. Take the opportunity to visit some of the many restaurants that overlook the Canal. Hopefully, local musicians will be playing Johann Strauss’ Blue Danube to entertain diners because the Danube is romantic by nature.

In Hungary, the river divides Budapest, the capital, into the old medieval city of Buda and the more commercial area of Pest. As you approach the city from the river, you will be welcomed by the Parliament— built in the image and likeness of London’s—and some royal bridges, such as the Chain Bridge, flanked by lions and the favorite of travelers. If during your visit to Budapest you glance at the Danube at night, beware: you may be overcome with a sudden feeling of melancholy.

(L) Budapest Parliament; (R) Golubac.

Built in the early 14th century by Hungarians, the Golubac Fortress, one of the most important monuments in Serbia, is another of the great surprises that await those who sail the Danube. In this region, the river reaches three miles wide. Here, the Serbs like to practice windsurfing, fishing and other water sports. After leaving Serbia, this majestic river flows through Romania and Bulgaria before reaching the Black Sea and putting an end to our historic and unforgettable journey. ■