Les Rochers-de-Naye, Switzerland A Story of the Future by artist Saype. The artwork covering approximately 6,000 square meters was produced with over 600 litres of biodegradable paint made from natural pigments, water and a milk protein and is part of the celebration for the 125th anniversary of the Glion Rochers-de-Naye train line

Photograph: Valentin Flauraud/EPA