One of the greatest engineering achievements in 19th century Switzerland and one of Freiburg's landmarks. The viaduct was designed by the engineer Leopold Stanislaw Blotnicki (1817-1879), a figure still poorly known despite his illustrious career. He was educated in civil and military engineering as well as architecture in Berlin, Vienna, Munich, London and Paris. His sojourn in Switzerland is recorded from 1853, when he became cantonal architect of Geneva (one of only two Poles to hold such a post in Switzerland, alongside Franciszek Stempkowski in Bern) and took part, among other things, in designs for the city's ring road. Around 1858, streets were cut through there to his design, and the Pont du Mont-Blanc was built. Despite later transformations, Geneva's modern transport network is largely the work of Blotnicki's urban planning. He also did, among other things, designs for a railway station for Lucerne and for Winterthur (1874), and a design for a railway tunnel under Meiringen in the Bernese Alps. The brilliant career of the chief engineer of the Swiss railways seems to have been interrupted by his sudden death, after which he quickly fell into oblivion. The Freiburg Viaduct remains the only one of his works remembered today. In 1856, Blotnicki took up the post of cantonal architect of Freiburg, but by 1859 he had already abandoned it, for unclear reasons. He then moved to the canton of Bern in connection with the construction of a large barracks complex in Thun.

In the 19th century, the viaduct structure was also admired outside Switzerland, both for technical and aesthetic reasons. In connection with the construction of the Lausanne-Bern railway line, it was decided in 1853 (on the basis of a preliminary report by Alexander Stryjeński, an engineer settled in Geneva) to throw the tracks high over the mountain river Sarina (Saane). Despite the negative opinion of British engineers, who considered the project too risky, after an international commission approved Blotnicki's design, construction was led by the French company Schneider &Co of Le Creusot in Burgundy. The realisation project was carried out by engineer Mathieu. A footbridge was provided next to the railway. Between 1925 and 1927, the bridge was changed to concrete with the participation of the prominent Swiss designer Robert Maillart (with the Błotnicki structure retained as the skeleton). The original structure was an iron truss, suspended 76 m from the water level and resting on six openwork pillars - each with a masonry plinth. Father Joseph Maria Bocheński, who lectures in Freiburg, called the viaduct 'an accidental masterpiece of art', which 'was created by concreting the metal structures of the railway bridge and no one thought about the aesthetic effect, but a kind of beautiful cloister was created' ('Memories', 1994). In 1987, a steel sculpture by the famous American artist Richard Serra was erected at the entrance to the viaduct, considered a tourist attraction.