Ranna

The Ranna is a northern tributary of the Danube flowing through the upper Mühlviertel in Upper Austria and Niederbayern. It rises in the Bavarian Forest south-east of Sonnen and winds southwards through largely untouched countryside. Near Obernzell it passes the village of Wildenranna before crossing into Austria at the Rannasee, a 20-hectare artificial lake created for bathing. The Rannastausee, known locally as the Mausloch, stretches for about 3.5 kilometres behind a dam built in 1954. A well-maintained footpath circles the lake, passing six Kneipp stations and a fitness trail. At its midpoint the Konzingersteg bridge links the two banks. Below the dam the Ranna cuts a deep gorge, the Rannatal, which has been designated a nature reserve and part of the Natura 2000 network. High above the gorge stand Schloss Altenhof and the ruined Burg Falkenstein. West of the valley lies Schloss Rannariedl near the Danube. The reserve’s steep slopes and cool microclimate shelter rare reptiles such as the smaragdeidechse and Äskulapnatter, alongside rich moss and lichen communities. Blockfields on the valley sides add further ecological interest.