The Danube flows through the following countries and cities (ordered from source to mouth). A list of the most important Danube cities can be find here:
Tuttlingen
Neuburg an der Donau
Ulm/Neu Ulm
Ingolstadt
Straubing
Regensburg
Deggendorf
Passau
Linz
Hainburg
Melk
Krems
Wachau
Vienna
Bratislava
Komárno
Štúrovo
Budapest
Györ
Visegrad
Esztergom
Dunaújváros
Paks
Baja
Kalocsa
Mohacs
Vukovar
Ilok
Osijek
Novi Sad
Belgrade
Viminacium
Donji Milanovac
Vidin
Corabia
Giurgiu
Galati - The biggest seaport on Danube
Tulcea
Sulina – the last city through which it flows