In the tucked away Black Forest town of Donaueschingen, the mighty River Danube begins. It rises as a clear, three metre-deep wellspring in the town centre, encircled by a stone basin sculpted with zodiac symbols. From there, the Danube – Donau in German – flows full tilt onwards for 1,771 miles to its mouth on the Black Sea, passing through the great cities of Vienna, Budapest and Belgrade. There’s so much poetry in that journey from dark woodland to dark water. But while my trip started at this blessed pool, where the Danube begins its course east, I was heading in the opposite direction – into a part of Germany’s south-west with which I was unfamiliar. Though the Black Forest is feted for its wild spaces, sense of remoteness and sweeping mountains – green in summer, top to bottom with snow-white thickets in the colder months – the region is easy to traverse year-round by boot, bike and Deutsche Bahn national rail. That’s good news for those who love discovering a new place by train, because the most compelling railway line here – the Höllentalbahn – begins in Donaueschingen, before rising 50 miles later in Freiburg, on the Black Forest’s western fringe. One of the steepest routes in the country, the Höllentalbahn has an equally gripping translation: the Hell Valley Railway. And I knew I was going to love it. It’s a good time for rail travel in Germany. Last summer, Deutsche Bahn launched a monthly subscription ticket for nationwide travel on local and regional routes for €49, while super saver fares for short distances were priced at €9.90 – and this is set to continue. Car emissions charges have since been increased and passenger numbers on local services have shot up by a quarter, according to Deutsche Bahn. That sense of sustainable value was also apparent on the Höllentalbahn. My entire ride cost €16, but I broke up the 90-minute journey with multiple stops along the way. Before I boarded, there was time to discover more of Donaueschingen. From the train station, I followed the road to Haus Fürstenberg, walking in the footsteps of the last emperor of Germany, Wilhelm II, a regular visitor to the princely residence. The grounds are filled with oak and birch, and, beyond the tree line, the palace rises like a Loire Valley chateau, its yellow facade crested with a top-hat dome. Inside, there is a stately but fun museum, home to a gilded travelling potty once owned by Napoleon. The atmosphere on the lakefront is fiesta-like, with timber-framed cuckoo clock shops, and pub landlords proffering foamy steins Next door, taking over several town blocks, is Fürstenberg Brauerei, a baroque palace of a brewery from the 18th century . It was a touch too early for a pilsner, but Kaiser Wilhelm II loved it so much, the beer became his majesty’s official beverage. My journey on the Höllentalbahn began shortly after, and following a quick transition from factories to farmland, the railway was soon in the thick of the Black Forest. To forge a straight route through the undulating highlands was impossible in 1901, when the line was completed, so the Höllentalbahn ducks and weaves like a heavyweight boxer. Slow at first, then landing punches as it passes several worthy stops. The first of these is Titisee, a glacial lake from which, according to legend, newborn babies entered the world. Nowadays, it’s a popular escape for spa tourism from spring to autumn, when visitors come to get their skin buffed baby pink. But as the darkening days segue into the snows of winter, Titisee comes into its own. The lake basin takes time to freeze, but when it does, the style and pace of life on the water accelerate, from leisurely boat cruises that run until late October to ice skating at Christmas and new year, when conditions are just right. The atmosphere on the lakefront is fiesta-like, with timber-framed cuckoo clock shops, pub landlords proffering foamy steins, and restaurant menus filled with the trappings of the season. With the lake yet to freeze, I made do with a shoreline stroll, then settled in at Seehotel Wiesler hotel. As I sat on the terrace facing the water, the owner’s son-in-law, Fabian Isele, stopped by to offer wine and local wisdom. “The best thing to learn about the Black Forest is, nature rules,” he told me. “Auerhahn [western capercaillie] live on Feldberg mountain. Wolves have returned, just like in a Grimm’s fairytale. So much is still untouched by our hands.” Reverence for the forest and the creatures within was also apparent the next day in neighbouring Hinterzarten, a short hop away on the train. The highest point on the Höllentalbahn (885m), Hinterzarten is the sort of village best suited to winter. Chimney smoke swirled from old-fashioned farmsteads. Byres stood ready with long-hipped roofs to withstand the wind and snow. A short walk from the train station, along a broad farm track, lies Ospelehof, one of the oldest steadings in these woods. Martin Braun is a wiry, fourth-generation farmer, dressed in lederhosen, who looks after a butchery, cheese shop, guesthouse and restaurant offering farm tours and raclette feasts in the dairy beneath his house. From Hinterzarten’s saddle, the train nosedived past waterfall hollows, sweeping us over the stone arches of the Ravenna Viaduct The restaurant’s warm basement setting offered respite from the cold and dry chill. Next to a copper kettle for churning out cheese, log benches sported woollen fleeces, and walls were draped with cow hides and framed portraits of Martin’s herd of Highland cattle. “I’ve always been a fan, but the topography is a challenge for them – and for me,” he said. “This is a world of forests, after all.” Together, we ate a platter of cheese intense with garlic from the surrounding wild lands, and claret-red beef salami and ham produced in Martin’s barn smokery. It was terrific. The most memorable part of the journey arrived that same afternoon, when the rail line crossed a landscape of banded hills scythed by gorges and bridges. From Hinterzarten’s saddle, the train nosedived past waterfall hollows, sweeping us over the stone arches of the Ravenna viaduct, with views over the narrow, deepening Höllental valley – hell, as early German visitors once called it, or Val d’enfer to the French. Contrary to this sense of moving into the Underworld, we hadn’t tumbled out of heaven or Earth. We’d merely plunged 400m. As the sun started to fade, the Höllentalbahn began its final descent through tunnels and twilight-lit trees, making its final stop at Freiburg station on the edge of the Black Forest. Passengers lurched off into the twinkling lights of the Altstadt, the old town, beneath gothic spires and stone gargoyles, and I happily joined the throng on showpiece Münsterplatz, or Minster Square, enjoying a pilsner and plate of roast goose and dumplings – a Black Forest dream. For many new arrivals, Freiburg is a reverie of a town, and, at this magical time of day, the culmination of my rail journey felt – almost – like a fairytale ending. Trip provided by Visit Germany. Double rooms at Seehotel Wiesler in Titisee from €98 B&B and Park Hotel Post in Freiburg from €149 B&B . Tickets for the Höllentalbahn can be bought online (bahn.de). Trains operated by Eurostar, TGV Lyria and Deutsche Bahn connect Donaueschingen and Freiburg to London in under seven hours (from £72, each way).