While beauty is subjective, the Glacier Express is widely considered the most iconic and visually stunning train in Switzerland. Often called the "world’s slowest express train," it connects the mountain resorts of Zermatt and St. Moritz over an 8-hour journey through the heart of the Swiss Alps. Passengers travel through 91 tunnels and across 291 bridges, including the famous Landwasser Viaduct. For the ultimate experience, the Excellence Class offers a "window seat guarantee," a regional five-course meal with wine, and a dedicated bar. Another top contender is the Bernina Express, which crosses the Bernina Pass at 2,253 meters and features the Brusio Circular Viaduct. While the Glacier Express is the epitome of luxurious, slow travel with gourmet dining, the Bernina Express offers more dramatic contrasts between snow-capped glaciers and the palm trees of northern Italy. Both utilize panoramic windows that curve into the roof, ensuring you never miss a moment of the breathtaking Alpine scenery.