After welcoming over 350,000 visitors, Milan’s Salone del Mobile closed its doors yesterday. As preparations for next year’s edition of the annual furniture fair are undoubtedly already underway, the city braces for an even bigger event in 2015 that is anticipated to bring 20 million pilgrims to the design capital over the course of six months.

Expo Milano 2015 will take place from May 1 to October 31, 2015. Though its pavilions will cover over 10 million square feet in a strategic area of the city between Malpensa airport and the Rho fairgrounds where the furniture fair just ended, the world’s next universal exposition is prioritizing immaterial legacies, leaving behind not a heritage of imposing architecture like the Eiffel Tower from the 1889 World’s Fair in Paris, for instance, but guidelines for tackling the challenges of the next millennium.

With the theme “Feeding the Planet, Energy for Life,” the aim of the Expo is to gather knowledge and skills from around the world in order to stimulate global debate and collaboration on the issues of hunger and access to clean drinking water. The challenge set by the Expo is to understand how to establish a new equilibrium between the available resources and nutritional demand of a growing world population that will reach nine billion people in 2050.

While larger nations will feature their own pavilions as in expositions past, 77 countries and two international organizations will jointly participate in nine clusters based around specific foods like coffee, cocoa, and rice. These exhibition spaces represent the first time in the history of the Universal Exposition—the first one arguably being the Great Exhibition that took place in the Crystal Palace in London’s Hyde Park in 1851—that exhibitors will not adhere to geographical groupings.

During his visit to Italy at the end of March, President Barack Obama made the announcement that the United States signed the Expo Milano 2015 participation contract. In a press conference, he said he expected Expo Milano to “engage and educate the world as only Italy can.” With the U.S. confirmation, the number of official participants increased to 147. (By contrast, Shanghai Expo 2010 had over 200 countries participate.)

The American pavilion has been designed to look like a granary. Visitors will be engaged in an itinerary “from farm to table” where video installations and vertical and roof gardens—representing the 50 U.S. states and the White House—will lead them to discover the rich cultural, scientific, and culinary tapestry that forms the country. A specific program of initiatives—the Manifesto Project—will be developed in support of corporate responsibility and environmental and food sustainability. A plan envisioning students’ involvement will also be launched in cooperation with Italian study projects at U.S. universities.

All pavilions will feature a sustainable and demountable design. And even though Expo Milano 2015 stresses the intangible legacies of the event, Expo organizers also hope to develop the site into a Smart City of the future.