The Danube is the second-longest river in Europe, with a length of 2,850 km (1,770 mi). It begins in the Black Forest in Germany and flows east to the Black Sea, forming the Danube Delta on its western coast. From west to east, the Danube passes through or borders ten countries, including four capital cities:
- Austria (Vienna)
- Slovakia (Bratislava)
- Hungary (Budapest)
- Serbia (Belgrade)
Unsurprisingly, each language has its own form of the river's name: die Donau in German, the Dunaj in Slovak, the Duna in Hungarian, and Dunărea in Romania.
The Danube is a major tourist attraction. Over the years, it has played an important role in the history of Europe. It passes through four capital cities as well as a number of other influential, historic and beautiful towns and stunning landscapes.
At the height of the Roman Empire in the first century AD, the Danube marked the country's northern border.
The Danube also coincides with a climate border; by and large crops such as grapes grow poorly north of the river.
- The Danube Cycleway runs the whole length, the German and Austrian sections being very popular.
- Donausteig from Passau to Grein (between Linz and Melk).
- Sultans Trail from Vienna to Smederevo (between Belgrade and Požarevac)
By canoe or kayak
Some ambitious canoe or kayakers attempt to travel the "length" of the river. Whilst some undertake the trip independently, others participate on the Tour - International - Danubien (TID). Run annually starting in Ingolstadt and finishing at the Black Sea, some join the TID for specific sections whilst a few attempt the entire Ingolstadt to Black Sea journey. However such a trip is a significant undertaking and requires skill and experience.
By cruise ship
There are many cruise liners along the river, some just short sections other, such as Avalon, Uniworld and Viking going from Passau to the Delta. Nearly all of the river is navigable, but cruises normally begin no further west than Passau, because the water is often too high for the boats to pass safely under some bridges, especially during the flood-prone spring season. During the dry summer months, the water may be too low, which commonly results in itinerary changes such as the need to change boats or riding a bus between two ports.
- Source of the Danube: Confluence of the headwaters Brigach and Breg near Donaueschingen. The InterRegioExpress rail line from here to Ulm almost exactly follows the course of the Donau.
- 1 Tuttlingen near the Danube Sinkhole
- Ulm. End of the IRE line from Donaueschingen. Train riders may transfer to the agilis to Ingolstadt which again follows the course of the river.
- Ingolstadt. End of the agilis line from Ulm. Another agilis line approximately follows the Danube to Regensburg (but bypasses Kelheim).
- Kelheim. This is where the Main Donau Kanal meets the Danube.
- Regensburg. End of the agilis line from Ingolstadt. Another rail line runs parallel to the Danube (but a few kilometres off its right bank) via Plattling to Passau (bypassing Deggendorf on the left bank). You can either use the ICE high-speed train or a local train to Plattling and then a regional express to Passau.
- Passau. From here the rail route continues parallel to the Danube to Linz, but does not follow the river's course. If you take the ICE or regional train to Linz, you will not see the Danube a lot. Travellers who place value on exactly following the river's course have to take buses to Jochenstein on the Austro-German border (only twice a day), cross the stream by ferry to Engelhartszell and continue by bus to Linz.
- Linz. From here intercity trains approximately follow the Danube to Vienna, but take a short cut and therefore do not pass through Wachau. So leave the IC in Amstetten and continue by regional express (REX) to Melk.
- Wachau: Cultural landscape that is considered one of the most scenic sections of the Danube and one of the most beautiful parts of Austria.
- Melk: huge Baroque Benedictine abbey, UNESCO World Heritage site. From Melk, busses take you through the Wachau to Krems an der Donau, following exactly the course of the Danube.
- Weißenkirchen in der Wachau
- Krems. Here you can get on a regional express train directly to Vienna (stopping in Tulln, but not Klosterneuburg).
- Tulln. You can change to Vienna suburban line S40 that stops in Klosterneuburg.
- Vienna. There are frequent rail links directly to Bratislava, but they bypass the beautiful Danube floodplains east of Vienna as well as the archeological site of Roman Carnutum and the small town of Hainburg an der Donau that is worth seeing. So better take the S-Bahn (suburban train) S7 to come by these attractions.
- Hainburg an der Donau. From Hainburg or Wolfsthal (the terminus of S7), continue by bus to Bratislava.
- Bratislava. From here there are direct Eurocity trains to Budapest (via Štúrovo, Visegrád and Vác). However, they do not follow the course of the river directly and you would miss the twin cities of Komárno/Komárom. Instead you could get off the EC at Nové Zámky and change to an ordinary train to Komárno.
- Komárno/Komárom. From the Hungarian half of the twin city, you could take an intercity train directly to Budapest (via Tatabánya), but you would miss the old royal city of Esztergom and the scenic Danube Bend, so this is not a real option. So better continue on the Slovak bank where there is a bus connection to Štúrovo.
- Štúrovo/Esztergom. Eurocity trains follow the course of the Danube from Štúrovo via Szob, Nagymáros/Visegrád and Vác to Budapest.
- Visegrád. You can get on a bus to Szentendre, but they bypass Vác. Vác and Szentendre are separated by an island between the Danube main stream and an anabranch and there is no bridge over the Danube in this section, so for visiting both you need to take a ferry from Vác and a bus from the island to the mainland town of Tahitótfalu. As this may get complicated, you might decide to visit only either this time.
- Vác. If you plan to visit Dunakeszi next, opt for a regional train, as the Eurocity does not stop there.
- Szentendre. Suburban train line H5 connects from Szentendre to Budapest in 40 minutes. It also has a stop at the ancient Roman site of Aquincum.
- Budapest. From Budapest there are international trains to Belgrade via Novi Sad, but their track runs rather distant from the course of the Danube, distantly bypassing the Duna-Dráva National Park at the border triangle of Hungary, Croatia and Serbia. Regional trains to Dunaújváros or buses to Baja (via Kiskunlacháza and Kalocsa) take you more closely along the river.
- Dunaújváros. You may either continue on the right bank of the Danube by bus to Mohács (via Szekszárd) or cross the river to Dunavecse where you can get on the bus to Baja.
- Mohács: small town close to the Duna-Dráva National Park.
- Sombor: Serbian town close to the Gornje Podunavlje Nature Reserve. Buses to Vukovar
- Vukovar (Croatia): Panturist buses to Novi Sad thrice a day
- Novi Sad: Train or bus to Belgrade
- Belgrade: Arriva buses through the Iron Gate to Kladovo (opposite Drobeta-Turnu Severin) three times a day
- Iron Gates Natural Park
- Orșova (Romania)
- Kladovo (Serbia, opposite Drobeta-Turnu Severin): Bortravel buses to Negotin
- Drobeta-Turnu Severin (Romania): Nikolic Prevoz buses to Negotin
- Negotin (Serbia): Nikolic Prevoz buses to Vidin
- Calafat (Romania, opposite Vidin): Buses to Turnu Magurele
- Vidin (Bulgaria): Buses to Kozloduy
- Kozloduy (Bulgaria): Buses to Pleven where you can change to a bus to Nikopol
- Turnu Magurele (Romania, opposite Nikopol)
- Nikopol (Bulgaria): Buses to Svishtov
- Zimnicea (Romania, opposite Svishtov): Buses to Giurgiu
- Svishtov (Bulgaria): Buses to Rousse
- Rousse (Bulgaria, opposite Giurgiu): Buses to Silistra via Srebarna
- Giurgiu (Romania)
- Tutrakan (Bulgaria)
- Srebarna Nature Reserve (Bulgaria)
- Silistra (Bulgaria, opposite Călărași)
- Călărași: Buses to Ciulnita from where there are trains to Fetești
- Fetești: Trains to Galați via Brăila
- Brăila: Bus to Tulcea
- Tulcea: Ferry to Sulina (mouth of the Danube)
- The 2 Danube Delta in Romania is a UNESCO World Heritage Site.