During his stay in Switzerland in 1946, Marcel Duchamp spent a few days at the Hotel Bellevue in Chexbres, high above the Lake of Geneva and one of Switzerland's most famous and attractive vistas. The nearby waterfall Le Forestay, cascading through the steeply sloping vineyards of the Lavaux towards the lake, inspired Duchamp's last great masterwork, the assemblage Aetant donnes: La chute d'eau, Le gaz d'eclairage . He photographed the scenery and included the image to his enigmatic work. The three-dimensional environmental tableau offers an unforgettable and untranslatable experience to those who peer through the two small holes in the solid wooden door. The artist-duo Caroline Bachmann and Stefan Banz found out where exactly Duchamp stood with his camera and reversed the situation. They took countless pictures of the breathtaking views of the lake, the high mountains of the Savoy Alps across and the vineyards of the Lavaux along its shore. Their work What Duchamp Abandoned For the Waterfall consists of more than 150 colour photographs, atmospheric images of one of Switzerland's most extraordinary and attractive landscapes. The new book What Duchamp Abandoned For the Waterfall presents this previously unpublished work for the first time. The accompanying essay looks at the artist's research on the relevance of Duchamp's Aetant donnes, how he made use of the location for his artistic intentions and what photographing this particular waterfall meant to him.