On the left bank of the Danube, southeast of Ardagger, comes the picturesque little town of Grein (239m/784ft), the life of which is closely associated with shipping. Above the town to the west towers the imposing Greinburg castle, which now houses the Austrian Shipping Museum. The castle, built in the 15th century, has a charming 17th century
arcaded courtyard. In the Stadtplatz will be found an unusual little Roccoco theater (1791) with seating for only 163; plays are performed in the summer months. As the boat sails past Grein, it enters a reach which was formerly a very dangerous stretch of rapids, the Greiner Strudel; the rocks were blasted away in the 19th century to make the passage easier.