The Danube does not flow through central Vienna. The city grew beside a braided, flood-prone stream that shifted its channels after every thaw, and between 1870 and 1875 engineers cut a single straight bed to the east. What remained beside the old town was the Donaukanal, a seventeen-kilometre arm now walled in stone quays and crossed by more than a dozen bridges. A Vienna Danube Lunch Cruise traces that inheritance, leaving the canal at Schwedenplatz for the regulated river the nineteenth century invented. Passenger traffic is older than the regulation. The First Danube Steamboat Shipping Company, founded in 1829, became the largest inland shipping concern in the world within fifty years, moving grain, salt, timber and emigrants between Bavaria and the Black Sea. Its successor, DDSG Blue Danube, still works from Franz-Josefs-Kai 2, a quay laid out in 1858 along the line of the demolished city walls. Vienna Danube Lunch Cruise tours therefore begin on a piece of Ringstrasse planning, where boulevard and waterway were conceived as one civic gesture. The banks read as an architectural chronology. Otto Wagner's Nussdorf weir, built between 1894 and 1898, guards the canal mouth with Jugendstil pylons and two bronze lions; his tiled Schützenhaus of 1908 stands just downstream. The Urania observatory, completed in 1910 to Max Fabiani's design, marks the point where the Wien river joins. Friedensreich Hundertwasser reclad the Spittelau incinerator in 1992, giving a municipal plant a gilded chimney and windows set at deliberate angles. Past the Reichsbrücke, which collapsed without warning in August 1976 and was rebuilt within four years, rise the aluminium curves of UN City, opened in 1979, and the 252-metre Donauturm of 1964. Between the river and its flood channel lies the Donauinsel, twenty-one kilometres of excavated island finished in 1988. The vessels themselves are shallow-draught craft, built low to clear the canal's bridges at high water. That density explains why a Donaurundfahrt remains a standard Viennese itinerary rather than a novelty. Land routes scatter these monuments across seven districts; the water assembles them. From mid-channel, Wagner's locks, Hundertwasser's chimney and the diplomatic towers appear in one continuous line, with the Kahlenberg vineyards closing the northern horizon. Johann Strauss composed "An der schönen blauen Donau" in 1867 for a men's choral society, and the waltz was, at its premiere, a modest success rather than a sensation. Vienna Danube Lunch Cruise tickets buy a rare legibility: a Danube River sightseeing perspective in which hydraulic engineering, imperial boulevard and postwar Vienna landmarks are read as a single sequence.