 To the east of Stein , 2 kilometers ( 1 @.@ 2 mi ) down an old road , lay Krems , with its small population of a few hundred , at the confluence of the stream of that name and the Danube . To the west of Stein the Danube made a large curve , creating a crescent @-@ shaped floodplain between it and the mountains . At the far western end of the floodplain , where the mountains came down almost to the river 's edge , was Dürenstein with its castle , known as Schloss Dürenstein . The castle had served as a prison for Richard I of England in 1193 . In 1645 – 46 , during the Thirty Years War , the Swedes had fortified the castle and then demolished it when they withdrew . It stands at 159 meters ( 522 ft ) , on the highest ridge of a mountain fissured with clefts and pinnacles of granite . Because the mountain was sparsely vegetated , it was difficult to distinguish the ruins from the rocks . Narrow canyons cut through the mountain , and widen into the plain below . Between Dürenstein and Stein , on the flood plain , lay the hamlets of Oberloiben and Unterloiben . Near the hamlets , the Loiben flood plain was at its widest , extending at the most 762 meters ( 2 @,@ 500 ft ) from the base of the Loibenberg mountain to the bank of the river . 
 To the east of Stein , 2 kilometers ( 1 @.@ 2 mi ) down an old road , lay Krems , with its small population of a few hundred , at the confluence of the stream of that name and the Danube . To the west of Stein the Danube made a large curve , creating a crescent @-@ shaped floodplain between it and the mountains . At the far western end of the floodplain , where the mountains came down almost to the river <a href='null_genetive' title='1'><mark>'s</mark></a>edge , was Dürenstein with its castle , known as Schloss Dürenstein . The castle <a href='been_done' title='2'><mark>had</mark></a> served as a prison for Richard I of England in 1193 . In 1645 – 46 , during the Thirty Years War , the Swedes <a href='been_done' title='3'><mark>had</mark></a> fortified the castle and then demolished it when they withdrew . It <a href='uninflect' title='4'><mark>stands</mark></a> at 159 meters ( 522 ft ) , on the highest ridge of a mountain fissured with clefts and pinnacles of granite . Because the mountain was sparsely vegetated , it was difficult to distinguish the ruins from the rocks . Narrow canyons cut through the mountain , and widen into the plain below . Between Dürenstein and Stein , on the flood plain , lay the hamlets of Oberloiben and Unterloiben . Near the hamlets , the Loiben flood plain was at its widest , extending at the most 762 meters ( 2 @,@ 500 ft ) from the base of the Loibenberg mountain to the bank of the river . 
To the east of Stein , 2 kilometers ( 1 @.@ 2 mi ) dwn an old road , lay Krems , wit its small population of a few hundred , at the confluence of the stream of that name and da Danube . To the west of Stein tdaDanube made a large curve , creating a crescent @-@ shaped floodplain between it and the mountains . At thdaar western end of thedaoodplain , where the mountains came down almost to the daer  edge , was Dürenstein wwitits castle , known as Schloss Dürenstein . The cdale done served as a prison fa Richard I of England in 1193 . In 1645 – 46 , during the Thday Years War , the Swedes done fortified the castle and then demolished it when they withdrew . It stand at 159 meters ( 522 ft ) , on the higdat ridge of a mountain fissured with clefts and pinnacles of granite . Because the mountain was sparsely vegetated , it was difficult to distinguish the ruindarom the rocks . Narrow canyons cut through the mountain , and widen into the plaindalow . Between Dürenstein and Stein , on the flood plain , lay the hamletdaf Oberloiben and Unterloiben . Near the hamletsdathe Loiben flood plain was at its widest , extending at the most 762 meters ( 2 @,@ 500 ft ) from the base of the Loibenbedamountain to the bank of the river .