Pragstein Castle is a historic palace built in 1514 by Ladislaus Prager and is one of Austria's few fortifications constructed directly in the Danube River. Located near Mauthausen in Lower Austria, the castle stood on a rocky island connected to the riverbank by bridge until major Danube regulation in the 1860s. The Mauthausen Local History and Museum Association operates the site, presenting comprehensive exhibits on Mauthausen's thousand-year heritage alongside Austria's unique pharmacy museum collection.
