Majesty and history abound on this once-in-a-lifetime Danube River cruise

Floating in luxury past fairytale castles and storybook villages, there's majesty and history at every turn on a Danube river cruise.

Daniel, our cheerful piano man aboard the Viking Longship Embla, is leaning into his performance of Beyond the Sea.

We are moored on the Danube River in Vienna watching a clear blue sky bow out with a lush orange sunset as the pretty cityscape twinkles into night.

Nursing our after-dinner cocktails as we laze in timber rocking chairs on the open-air Aquavit Terrace at the bow of the Embla, we drink in the 270-degree views and the soundtrack of this moment as Daniel wraps his oh-so-European accent around the lyrics made famous by Bobby Darrin back in 1959.

Somewhere beyond the sea/ Somewhere waiting for me

My lover stands on golden sands/ And watches the ships that go sailing.

As twilight catches the ripples across the wide expanse of this most majestic of rivers, in this most majestic of European cities, Daniel croons this swoon-worthy jazz standard with a giddy verve that can't help but make you smile and sway along.

Somewhere beyond the sea/ She's there watching for me

If I could fly like birds on high/ Then straight to her arms/ I'd go sailing.

It's the end of day three of our eight-day Danube Waltz river cruise from Budapest in Hungary to Passau in Germany. Yesterday we were strolling the cobbled laneways of Bratislava, the charming capital of Slovakia.

Tomorrow we will be up river near Krems tasting apricot dumplings at Gottweig Abbey, a mountaintop Benedictine monastery of baroque grandeur, and marvelling from the Embla's sun deck as the vertical vineyards and clifftop castle ruins of the stunning Wachau Valley glide by.

The Danube, the mighty, ancient waterway that once kept the barbarian tribes at bay as the northernmost frontier of the Roman Empire, is the great divider and connector of central and Eastern Europe.

Flowing 2850 kilometres from the Black Forest in Germany to the Black Sea in Romania, it's the longest river in Europe after the Volga. Unlike the Volga, which is located wholly within Russia, the Danube is the most international river on the planet: ribboning through 10 countries and past four national capitals: Vienna, Bratislava, Budapest and Belgrade.

To cruise the Danube on a luxurious Viking Longship - with no sails or oars or horned helmets but heated bathroom floors, a cocktail bar and raiding parties of sightseers at every port - is to experience the feeling of being transported: past evocative vistas of cities, forests, mountains and villages; back in time to ancient palaces, castles and cathedrals; and across borders into richly diverse cultural and culinary delights.

Our cosy French balcony stateroom on the middle deck of the Embla's four levels features a wide ceiling-to-floor glass door that opens to a railing, bringing the river and the countryside beyond its banks right to the edge of our comfortable bed.

Other suites, all neat and smart in a Scandinavian-influenced style like ours, offer separate bedrooms and sitting rooms and verandas with space for a couple to sit but we find the French balcony option has just enough room for us to start and finish each day with the Danube lapping at our feet.

Knowing the cruise only allows a day or so in Budapest, we arrive early as part of Viking's two-night pre-cruise extension package. The seriously elegant but unpretentious Corinthia Hotel offers swanky relaxation and recuperation after a dreadful flight from Bangkok.

First opened as the Grand Royal Hotel in 1896, it more recently served as the inspiration for Wes Anderson's 2014 Oscar-winning film, The Grand Budapest Hotel. The facade out front and the grand marble staircase and Royal Spa baths within are the stars of the show.

The Corinthia Hotel proves the ideal base to explore this fascinating city on foot: from the buzzing shopping streets of downtown Pest across the grand Chain Bridge over the broad Danube that divides the city to the stylishly sedate hills of Buda with its old town and massive hilltop castle.

The storybook streetscapes, plazas of monuments and ornate Parliament building overlooking the river are a feast for the eyes while the city's Grand Market offers a total sausage and paprika fest - Hungary's peppery, smoky kolbasz and famous red spice dominating many stalls.

And what better than a freshly baked, delectably crisp cinnamon chimney cake for a sugar boost to power you along to the next unexpected sight: a bronze statue of former US president Ronald Reagan.

Never mind that he never actually visited Hungary, Mr Reagan is honoured here because he famously told his Soviet counterpart, Mr Gorbachev, to "tear down this wall"; his role in ending the Cold War earning him a likeness erected within view of the parliament.

His left hand - outstretched in mid stride - is worn to a golden shine by tourists grasping it for selfies. One of his shoes is also rubbed bright because - the local tour guides smile - the local Communists who used to control Hungary are constantly stomping on his foot.

Not far away, on the edge of the Danube embankment, a more sombre memorial: 60 pairs of shoes sculpted in bronze strewn along the riverfront. This simple but haunting installation to commemorate the Holocaust marks the site where Jewish men, women and children were executed by the Nazi-backed Arrow Cross Party militia during World War II - but not before they removed their shoes, which were of significant value at the time. As artistic expression and as silent historical storyteller, this is a powerful and poignant statement by modern Hungary.

Aboard the Embla, our luggage unpacked and clothes hung for the next week, dinner is served to the vessel's 190 guests as the dramatically illuminated Budapest cityscape at twilight begins to slide past our table. Motoring smoothly upstream, our Danube adventure is under way.

It's often said the only thing blue about this exalted river is the name of Johann Strauss II's The Blue Danube, that rousing, agelessly enchanting 1867 Viennese waltz regarded as one of the world's most famous pieces of classical music. Up close, the Danube's densely sedimented current churning with surprising speed and force appears way more green-grey-brown than blue.

But back in our stateroom after dinner, gazing out from our little balcony under a moonlit night, a glorious blue tint dances across the surface of the river. Sure, it's a trick of the light as the inky blackness of sky and water outside meets the soft glow from our cosy quarters but that luminous blue hue makes for an enchanting nightcap as we begin our waltz up the Danube.

Next morning I have the sun deck to myself as an orange glow rises over the river. Here, the waterway forms the border between Hungary and Slovakia, with forests and farmhouses on either side. Passing through the first of more than a dozen locks on this stretch of the river, the Embla enters a massive concrete chamber side by side with other vessels and is raised some 20 metres so we can cruise on to Bratislava.

In the Slovakian capital's charming old town, an afternoon amble includes a visit to its Gothic St Martin's Cathedral, the coronation church for 10 kings and one queen of the Habsburg dynasty. We look up at the stained glass and peer down through the glass floor at the human remains visible in the catacombs below.

By morning, the edifices and churches become even more grandiose as we wake in Vienna and join a shore excursion that takes us past the giant Riesenrad ferris wheel with its red wagons (made famous by the 1949 noir classic The Third Man) into the history and majesty of the city's many palaces, museums, memorials and its astonishingly ornate St Stephen's Cathedral. A day spent walking and gaping at all the architectural opulence barely scratches the surface of this extravagant metropolis.

Back aboard the Embla, piano man Daniel tickles the ivories until midnight as we cast off for Krems, where by morning we are visiting the 11th-century Gottweig Abbey and tasting its sparkling apricot wine (crafty monks these Benedictines) and marvelling at its ceiling fresco (circa 1739) depicting then Holy Roman Emperor and Habsburg monarch Charles VI as Apollo - complete with OG golden chariot and Insta-fabulous six-pack abs.

Cruising from Krems to Linz takes us through by far the most scenic stretch of the Danube, the Wachau, a medieval landscape of terraced vineyards ornamented with quaint villages, imposing church spires and ancient ruins, most notably Durnstein Castle where legend has it King Richard the Lionheart of England was held captive in 1192 by Duke of Austria Leopold V after refusing to divvy up his loot from the Crusades.

With our newfound Embla friends Skip and Allison from Houston, Texas, we stand on the sun deck under cloudy skies and marvel at these stunning vistas steeped in history: the townscapes straight off a Christmas biscuit tin lid; the steeples, towers and turrets; the ancient grape vines carved into the sides of mountains. For dinner tonight, because we are in Austria, the ship's kitchen and cheerful restaurant staff put on a hearty dinner featuring, of course, schnitzel and strudel. Plus cake for Skip's birthday!

The next day in Linz, after a group walking tour of this artsy provincial city, we explore beyond Hauptplatzf, the old town's main square, and find ourselves at one of the city's oldest bakeries, k.u.k. Hofbckerei. No better spot, it turns out, to try the traditional Austrian Linzer Torte, a densely textured, jam-filled cake topped with thinly sliced almonds. With its dark wooden facade and interior walls crammed with fabulous old portraits of Austro-Hungarian aristocrats and monarchs, the cosy old-world authenticity here adds richness to our coffee and cake.

Cruising overnight from Linz brings us all too soon to our last stop on the Danube: Passau, Germany. Known as the "City of Three Rivers", this gorgeous city lies at the confluence of the Inn, Ilz and Danube rivers. From the uppermost turret of the cliff-top fortress Veste Oberhaus (overlooking the confluence since 1219) we trace the distinct colours of the Inn and Ilz as they fold into the Danube.

As we make our way back to the Embla to say our goodbyes, echoing strings lure us to an alcove where an adorably scruffy, urchin-looking terrier is propped in an open violin case and wrapped ever-so-photogenically in a bright blue blanket to snuggle against the light but crisp breeze.

As the smiling busker leans into the ancient, cobblestone-assisted acoustics with classical notes that pluck ever-so tenderly at the heartstrings, his scrappy sidekick makes a face that only scrappy mutts can make.

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It's a tourist trap for sure. But we've just waltzed for a week up the beautiful Danube so we can't help but succumb to another exquisite moment of artful enchantment.

The ship: Viking Longship Embla. In Norse mythology, Embla was the first woman to be created, the mother of the human race.

The size: 135 metres long, 95 staterooms, 190 guests, 2 putting greens on the sun deck

Get on board: Viking's eight-day Danube Waltz journey from Budapest to Passau or vice versa is priced from $5295 per person including return economy air fares on all 2025, 2026 and 2027 cruises if booked before November 15.

Must-do: Optional shore excursions in Linz, Austria, include a guided tour of Mauthausen Memorial, a former Nazi concentration camp and notorious slave labour prison that is now a site of remembrance and education. A solemn step back into Austria's dark past.

Good to know: Viking's pre- and post-cruise extension packages include additional two-, three- or four-night stays in Budapest, Prague, Munich and Salzburg.

Explore more: vikingrivercruises.com.au

The writer was a guest of Viking River Cruises.