Originally founded by the Celts and later an important Roman settlement, Regensburg is one of Bavaria’s lesser known gems. Situated on the northernmost bend of the Danube, it’s a friendly and laid back city, with an exceptionally well preserved medieval centre.

The pretty Bavarian town of Passau, situated close to Germany’s border with Austria, enjoys a unique setting at the confluence of three rivers: the Inn, the Ilz and the Danube. The narrow cobbled streets of the handsome old town, the Altstadt, are quite delightful.

The city of Linz is included on river cruise itineraries due to its proximity to Salzburg, which is where you’ll most likely be headed. Salzburg’s Altstadt attracts millions of visitors every year with its fairytale skyline of domes and spires, and the city is renowned as both the birthplace of Mozart and the setting for ‘The Sound of Music’.

The riverside village of Melk is best known for its spectacular abbey, a Baroque masterpiece that dominates the landscape. A Benedictine abbey was first established here in 1089, and the 18th century reconstruction that you can see today is still a working monastery.

Formerly the centre of the Habsburg Empire, Vienna is as grand a European capital as you can imagine, jam packed full of thrusting, bombastic buildings that stand as a reminder of Austria’s glorious imperial heyday.

Budapest is one of Eastern Europe’s most appealing cities, a vibrant and welcoming capital that straddles the Danube. The history of Budapest has been somewhat turbulent, but plenty of beautiful buildings survive, including the imposing Parliament and iconic St Stephen’s Basilica.

Mohács was the scene of a decisive battle in 1526 that brought Hungary under Ottoman control, but is best known these days for its Busó carnival in February, when men in creepy-looking costumes take to the streets to celebrate the end of winter. The town is also a jumping off point for the attractive city of Pécs, half an hour’s drive away.

Novi Sad is a vibrant and friendly city with a lovely riverside setting. Handsome Austro-Hungarian architecture is a reminder of past glories, while the imposing Petrovaradin Fortress has become the unlikely setting for one of Europe’s biggest music festivals, Exit, which began life as a student protest against the government.

Belgrade has been invaded and occupied dozens of times over the centuries, a fact that's reflected in the mish-mash of architectural styles, from Ottoman and Art Nouveau to grim relics of the communist era. But Belgrade is also a city with real soul, emerging from a difficult recent history as one of Europe’s most exciting capitals.

The riverside town of Vidin is situated in the north west corner of Bulgaria, close to the border with Romania and Serbia. The architectural highlight is the magnificently well preserved Baba Vida fortress, and the town is also home to a mosque, a synagogue and several churches.