There’s a Mediterranean flavour to the former capital of Bavaria. Could it be the tall narrow streets of Regensburg’s old city, which could easy have been transported from Nice to give shade from the midday sun? Or the plazas and piazzas surrounded by ice-cream parlours, which could so easily be somewhere on the Italian Riviera? Or even the robed Dominican, Benedictine or Carmelite figures fluttering down cobbled alleys, reminiscent of Rome’s Vatican city?

In fact Regensburg was once the seat of the Imperial Diet of the Holy Roman Empire, an empire which – despite the name – was much more to do with central Europe than it was with Rome. It was the power base for Emperor Charlemagne, and it remains essentially medieval in its layout. The city has 1,400 buildings of serious historical significance still standing, many of them more than 500 years old. The Porta Praetoria, one of the original Roman gates, is over 2,000 years old.

The best place to get a snapshot of this epoch-straddling place is out on the Steinerne Brücke, a magnificent bridge built back in 1130 and which for many centuries was the only Danube river-crossing between Ulm and Vienna. That bridge played a huge role in Regensburg’s growth, giving it unprecedented historical importance in trade, religion and politics. It remains a hefty piece of stonework, and from its centre, pedestrians can look back at a medieval skyline studded with towers, with the soft yellows and ochres of old walls producing a fading fresco on the riverbank.

Salt and sausages

A lot of those riverside buildings were originally storehouses for river-borne cargo, particularly salt, and all this trade imbued the city with a cosmopolitan spirit. The key salt-trading building, the Salzstadel right by the Steinerne Brücke, is this year hosting a new visitor centre marking five years since the city became a UNESCO World Heritage Site.

Also down by the waterside, just along from the bridge, is what is supposedly the oldest restaurant in Germany. The Sausage Kitchen is a low stone cottage with a tall chimney, unmissable not because of its architecture – it looks like a Greek quayside taverna – but because of the all-pervasive smell of grilling Wurst, which are still homemade. Its customers are in good company, for Goethe, Mozart and Haydn all ate here.

Today Regensburg continues to produce its celebrities. The recently-retired Pope was mere Cardinal Ratzinger during his formative years as a professor at the university, and would have been a regular presence in Regensburg’s impressive Cathedral.

So also has been Princess Gloria von Thurn und Taxis, one of the most controversial of Germany’s aristocrats. She still lives in part of the Thurn and Taxis Palace, a former monastery close to the heart of the city. The palace is almost a town in itself, with the outlying areas given over to museums, galleries, a brewery and restaurants. Between them its 500 rooms amass 14,000 sq metres of parquet flooring, several Gobelin tapestries and a crystal chandelier which weighs more than a ton. Every July the palace hosts a major arts festival, the Thurn und Taxis Schlossfestspiele, with concerts, opera, musicals and fireworks in the courtyards.

But despite the size and the grandeur of their home the Thurn und Taxis family does not have an immensely long tradition in Germany. They were originally Italians, which somehow seems appropriate for Regensburg.