“Expo 2000 Hannover” took place in Hannover, Germany, from June 1 to October 31, 2000. Organized by Expo 2000 Hannover GmbH, it was a universal exhibition under the second categorization system of the International Exhibitions Bureau (Bureau International des Expositions, BIE). Its theme was “Humankind, Nature, Technology.” The Expo occupied 160 hectares and recorded about 18 million visits.

The member states of the BIE chose Germany as host at the 107th General Assembly in June 1990, a few months before German reunification. Hannover’s only rival was Toronto, and the decision could hardly have been closer: Hannover won by a single vote. Support at home was also narrow. In a 1992 referendum, with a turnout of 61.7%, 51.5% of Hannover’s voters approved the Expo and 48.5% opposed it.

Germany invited the world to present visions of a future society that would balance people, nature and technology. The theme drew on Agenda 21, the action plan adopted at the 1992 Earth Summit in Rio de Janeiro, and was divided into subthemes that included environment, energy, mobility, knowledge, information, health and nutrition. A Thematic Park at the heart of the site presented possible solutions in fields such as knowledge, basic needs, health and energy. Through the “Projects Around the World” initiative, an international jury selected exemplary projects, which were presented in the Global House, while the Global Dialogue brought together partners from different countries before, during and after the Expo.

About 155 countries took part in the Expo’s thematic exchanges. Several national pavilions became landmarks of contemporary architecture. Peter Zumthor designed the Swiss Pavilion from some 45,000 planks of unseasoned timber, assembled without glue. Shigeru Ban designed the Japan Pavilion using paper tubes made from recycled German paper. The Netherlands Pavilion by MVRDV stacked a tulip field, a forest, sand dunes and wind turbines in a 40-meter structure that generated its own electricity and recycled its water.

Sustainability shaped the site. In June 1994 the BIE General Assembly had resolved that organizers must plan for the reuse of Expo sites and infrastructure, and Hannover followed strict guidelines known as the Hannover Principles. Most of the grounds were developed from the existing Hannover Messe exhibition grounds, and new land on the Kronsberg hill was planned together with a residential eco-district of low-energy and passive houses. Federal and state governments invested more than four billion marks in the region’s transport network, adding tram, metro and railway connections and upgrading roads, the main station and the airport.

The cultural program, “Where Worlds Meet,” extended across the Expo site, the city and the surrounding region. Highlights included Peter Stein’s uncut, 21-hour staging of Goethe’s “Faust,” and performances by Pina Bausch, Luciano Pavarotti, Santana, Compay Segundo and Joaquín Cortés. Each evening before closing, a light and sound show called Flambée played over the Expo lake. The mascot, Twipsy, designed by Javier Mariscal, also starred in a 52-episode animated series broadcast in 90 countries.

Attendance fell far short of expectations. Organizers had planned for about 40 million visitors, and the shortfall left a deficit of about 2.4 billion marks for the German public budget. Critics also questioned the Thematic Park’s reliance on spectacle and corporate sponsors, as well as the Expo’s overall environmental balance for the region.

The Expo’s physical legacy proved more lasting. The Kronsberg district became a reference for ecological housing, social mix and landscape design, and new facilities, including an arena, remained in use. Several pavilions found second lives: Mexico’s became a library for a university in Braunschweig, Ethiopia’s returned to Ethiopia, and Belgium’s became a recording studio. The BIE also identifies the Global House as the forerunner of the best practices areas presented at later Expos, beginning with Expo 2010 Shanghai.

Expo 2000 Hannover placed sustainable development at the center of its theme, its site and its programs. Despite its financial difficulties, it helped change what organizers and the BIE expect an Expo to address and to leave behind.