The Our is a mountain stream that collects its water from over 600 springs. It originates at Loshaimergraben in Belgian territory and runs largely along the Belgian-German and Luxembourgish-German borders. After approximately 100 km, the Our flows into the Sauer. Especially at the upper reaches, the Our flows largely untouched and forms meanders, which provide a habitat for numerous species. The cool and oxygen-rich water of the Our is ideal for brown trout, bullheads and brook lampreys. The rare freshwater pearl mussel can also be found here on occasion. Alders, birches and willows grow on the banks of the river Our to fortify it. This creates an ideal habitat, for example, for the water ouzel – one of the few birds that can both swim and dive.