The Moselle's 544-kilometre arc from France to the Rhine carved Germany's steepest vineyard slopes — terraces planted by Romans two millennia ago still yield Riesling today. Between Cochem and Beilstein, the river coils through a valley so narrow that medieval engineers built fortresses on every promontory: Reichsburg Cochem's ochre towers loom 100 metres above the water, its ramparts visible from the deck of every vessel threading the channel below. The cruise route navigates a working waterway, where lock chambers lift passenger boats and cargo barges alike past weirs installed in the 1920s to deepen navigation channels. Steamship service on the Moselle began in 1841, when paddle-wheelers ferried wine barrels to Koblenz faster than ox carts could manage the valley road. By 1900, tourism eclipsed freight — daytrippers from Cologne and Frankfurt rode open-deck vessels to taste wine at riverside cellars. Today's panoramic cruises follow those century-old routes, departing Cochem's Moselpromenade terminal every 90 minutes between April and October. The fleet includes modern salon ships with retractable glass roofs and vintage paddle-steamers that still burn oil in their boilers. Most sailings last 50 to 90 minutes, looping to Beilstein or Alken before turning back through the same lock systems. The valley's architecture reflects a thousand years of contested borders. Half-timbered burgher houses in Beilstein date to the 15th century, when the village thrived as a toll station; Reichsburg Cochem was rebuilt in neo-Gothic style after Prussian industrialists bought the ruin in 1868. Vineyard plots remain divided as they were under Napoleonic law — single hectares split among a dozen families, each tending rows that climb 60-degree slopes accessible only by Moselsteig footpaths. Spring cruises pass blossoming apricot orchards; autumn sailings glide through valleys hazed with harvest smoke. The river's meanders slow currents to a walking pace, allowing vessels to drift past slate cliffs and stone cellars without engine noise drowning the valley's quiet.