As a schoolboy I was fascinated by the Iron Curtain, later as a student exploring Europe by train, I crossed into East Germany at night. The surly border guards and brusque body searches in the wee small hours did little to promote tourism. But that was before the summer of 1990 by which time all of the former Communist regimes of Eastern Europe were replaced by democratically elected governments. With this in mind, I relished the prospect of a river cruise through Hungary, Croatia, Serbia, Bulgaria and Romania. Would my Balkan voyage evoke memories of the Cold War or would the welcome be as warm as the summer sun?

Rising deep in the Black Forest Mountains, the meandering Danube forges an easterly course on its inexorable path towards the Black Sea. This fabled waterway is a cultural lifeline that’s proved a hit with tourists, so much so I had sailed its upper reaches in Austria and Germany on a variety of river cruise vessels. Now aboard a Viking Longship, I was about to sail the less travelled, but no less spectacular, Eastern Danube.

I joined the 11-day ‘Passage to Eastern Europe’ cruise tour in Budapest and after two nights in a deluxe hotel, I embarked the Scandi-chic Viking Idun. As the engines rumbled into life, we passed the illuminated façades of some of the Hungarian capital’s most iconic buildings bathing the Danube in sparkling golden light. My voyage to Bohemia and beyond had begun.

An organ recital in Kalocsa’s baroque 18th century Assumption Cathedral preceded the spectacle of skilled horsemanship at the Bakodpustza Equestrian Centre. At Vukovar in Eastern Croatia, the included excursion headed to the baroque gem of Osijek. In the Serbian capital, Belgrade I joined an optional ‘behind the scenes tour’ of the National Theatre which concluded with operatic arias performed by an accomplished soprano and tenor.

Separating Serbia from Romania, The Iron Gates are four narrow gorges that create an 83-mile stretch of waterway bounded by steep cliffs. I had my camera ready as we sailed past a giant rock sculpture of King Decebalus; later our captain deftly navigated the Djerdap locks of the Iron Gate Dam, lowering the vessel 63 feet to sea level.

Departing the forlorn Bulgarian port of Vidin a tour took me to Belogradchik where formidable rock pinnacles rise above the Kaleto Fortress, a lofty lookout built by the Romans. From Ruse, a whole-day tour visited Veliko Târnovo, one of Bulgaria’s oldest towns renowned for its historic lanes and 19th-century buildings; as well as the village of Arbanassi, where ancient frescoes adorn tiny churches. From the Romanian capital of Bucharest, I took a three-night extension trip to Transylvania where Peles Castle and Bran Castle are famed for the myth created around Bram Stoker’s Dracula. It was a remarkable conclusion to a revealing voyage through lands free from the shackles of Cold War politics.