"Blue - Inventing the River Danube" connects the cultural history of the river with an artificial research in the presence. The view is directed eastwards and follows the course of the river from Vienna to the estuary mouth. With historical photo-material, most of which is from the collection of the Technical Museum in Vienna, the development of the river is described as is its meaning as a European waterway since the 19th century. The two photographers, the French artist Sophie Ristelhueber and Iosif Király from Romania, are broaching the issue of the present river. In winter and spring 2004/2005 both travelled along the River Danube eastwards and westwards. Iosif Király visited places of the middle and lower River Danube which are affected by the industrial era. He photographed the former dockyards in Budapest and the seaports Turnu-Severin, Giurgiu und Brãila. Sophie Ristelhueber concentrated her work on the river-ending, the delta and the city of Sulina where the river Danube ends and the Black Sea begins.