Created for Expo 64, this garden has since been used to teach children about road safety. Designed in the image of the 1960s city, the site today presents all the contemporary challenges from the all-car, to the sparse presence of vegetation, to impermeable mineral soils and clear water drainage. These design features lead to overheating— through the urban heat island effect—while rainwater runoff overwhelms sewers and waterways.

Sixty years on, the site is undergoing a transformation for Lausanne Jardins 24 : the slope gradients have been recalculated, new ditches and a new pond have been created, gravel has been removed, surfaces have been lightened to reduce the albedo effect, plants have been added, and grids have been disconnected. Although the garden retains its original function, it is now a life-sized testing ground for the sponge city—and a tool for raising awareness of the relationship between city and nature.