925 000 square metres of Planetary Garden is how architects Stefano Boeri, Richard Burdett, Mark Rylander and Jacques Herzog imagine Expo 2015.

Presented in 2009, it’s still not known if their project is feasible. It proposes a natural capital, thanks to an enormous perennial garden, a sort of planetary botanical park set on a grid of roads and paths and surrounded by canals and landscaped areas.

There is a central boulevard for pedrestians and cyclists, with areas to stop and relax, look at the national pavillions and taste the foods grown and prepared by them. There are huge bio-climatic greenhouses reconstructing the main ecosystems of our planet, from tropical forest and Mediterranean landscape to the tundra and the extremes of the poles and the desert. Around the perimeter are a series of navigable canals, with water purification systems to clean and recycle water from within the site.