Japanese architect Sou Fujimoto has created one of the most remarkable architectural achievements of the 21st century with his Grand Ring at Expo 2025 Osaka, a massive circular timber structure that serves as the centerpiece of the world exhibition running from April 13 through October 13. The structure, built on a former garbage dump island in Osaka's Yumeshima district, has earned recognition from Guinness World Records as the world's largest wooden building, covering approximately 657,000 square feet.
The environmental and cultural implications of modern world exhibitions continue to spark debate among critics and architects alike. Like grains of sand slipping through an hourglass, justifications for these global gatherings are becoming increasingly questionable in an era of widespread international tourism and digital spectacle. The environmental impact of millions of visitors traveling across the globe to attend temporary exhibitions is staggering, while their geopolitical relevance in an increasingly fragmented world order remains uncertain.
Historically, the fate of Expo sites after closure has been mixed at best. Montreal's Expo 67 site stands as a rare success story, transformed into a beautiful riverside park crowned by Buckminster Fuller and Shoji Sadao's geodesic dome, now the Biosphere Museum, alongside Moshe Safdie's iconic Habitat residential complex. In stark contrast, New York's Flushing Meadows-Corona Park, site of both the 1939 and 1964 World's Fairs, remains one of the most neglected spaces in the metropolitan area, serving as what critics describe as an "urban lint trap" largely ignored by passersby.
Despite these concerns, world expositions have historically provided platforms for architectural innovation. Legendary figures including Gustave Eiffel, Joseph Paxton, Le Corbusier, Konstantin Melnikov, Charles and Ray Eames, Kishō Kurokawa, MVDRV, and Diller Scofidio + Renfro have all used these venues to explore groundbreaking ideas and advance their fields. Given that the architecture industry spends far less on research and development compared to automotive, energy, healthcare, and defense sectors, Expos remain valuable opportunities for experimentation.
Fujimoto, now 54, represents one of the youngest Japanese architects to achieve such international recognition through a series of impressive buildings. His architectural journey began with the 2010 Musashino Art University Museum and Library in Tokyo, which revealed his eclectic design sensibility combining the lightness and transparency associated with his mentor Toyo Ito while radiating warmth through strategic wood deployment throughout the interior. Unlike many contemporary architects, Fujimoto lacks a signature style, which may explain why he remains less known outside architectural circles despite extensive coverage in the 2010 issue of El Croquis.
His shapeshifting architectural approach can range from the austere minimalism of Kazuyo Sejima to the tectonic complexity of Kengo Kuma. The 2013 Serpentine Pavilion in London, inspired by Mies van der Rohe's Barcelona Pavilion, demonstrated his innovative thinking by creating an open lattice structure of white steel pipes that functioned as much as a jungle gym as a building. This project consolidated his reputation as an imaginative global architect capable of producing clever, elegant designs.
Early in his career, Fujimoto's reading of Ilya Prigogine's chaos theory sparked a lasting interest in the emergence of order, influencing his thinking about human behavior in public spaces. The forest became a central metaphor in his work, not merely because of his use of wood or forest settings, but due to how forests regulate the relationship between humans and nature. These concerns culminated in his 2014 House of Music in Budapest, where trees grow through the building's irregularly shaped spherical roof, achieving the synthesis of architecture and environment he had long pursued.
The Grand Ring represents the culmination of three decades of design exploration rather than a standalone creation. Its circular form and double helix ramps clearly draw from his unrealized 2011 design for the Beton Hala Waterfront Center in Budapest. Although the densely packed core prevented identification of his intended "Forest of Silence," the structure successfully embodies his architectural philosophy.
As the central organizing element of Expo 2025, the Grand Ring encircles the entire fairground while simultaneously serving as observation platform, roof garden, climate control system, and infrastructure hub. This multifunctional design allows easy navigation to pavilions from 160 countries and dozens of organizations. Even during hot and humid summer days, the underside of the structure remains surprisingly cool, thanks to the Japanese concept of ma—a space allowing natural ventilation and shade.
The construction utilized 70 percent Japanese cedar and cypress combined with 30 percent foreign wood, primarily Scots pine. However, the structure's scale raises environmental concerns, as it consumed nearly one percent of all timber in Japan—a staggering figure for any single temporary construction. The building process, which began in June 2023, employed traditional thousand-year-old Nuki joinery techniques from Kiyomizu-dera temple in Kyoto, combined with modern engineering. The construction uses no nails or screws and includes metal reinforcement for seismic safety.
Structurally and aesthetically, the Grand Ring evokes associations with temple architecture, the Roman Colosseum, the High Line, 19th-century exhibition halls, and massive sports stadiums while maintaining its unique identity. This remarkable fusion of old and new, Japanese and Western architectural traditions demonstrates boldness reminiscent of Kenzo Tange's finest work. The building achieves what Aldo Rossi called the "adequate synthesis" required of the modern age.
Unlike the typically propagandistic national pavilions with their flashy designs and wall projections of sweeping landscapes, the Grand Ring stands as the most memorable, functional, and culturally rooted architecture at the Expo. The building's Skywalk, positioned about 100 feet above ground and accessible via stairs, elevators, and escalators, offers stunning views of the fairground below, the Seto Inland Sea, and the distant Kansai Airport island.
Walking the structure's perimeter at a leisurely pace takes approximately 50 minutes, during which the building occupies visitors' entire visual field. Despite its immense size—about 2,200 feet in diameter and 100 feet wide—the structure never feels monumental or oppressive. Flower beds and vegetation illuminated by pinpoint lighting at night, combined with the intriguing double helix ramp system, break up visual monotony while accommodating large crowds without feeling cramped or dangerous.
Visitors demonstrate remarkably civilized behavior both on and below the roof, creating what may qualify as one of the great public spaces of this century. The building achieves the rare feat of feeling intimate and sophisticated without being over-designed or off-puttingly functional, managing crowds with grace while maintaining its architectural integrity.
The structure's fate after the Expo closes remains uncertain, though plans are emerging for its future. According to expo officials, two sections measuring approximately 200 and 350 meters are being considered for permanent installation and will be excluded from current reuse planning. The remaining structure will be carefully dismantled for reuse in other buildings and projects, with some requests already received. Materials that cannot be reused will be processed into wood chips for fuel or other sustainable applications.
However, this optimistic narrative tells only part of the story. According to NHK daily reports, only eight percent of the Ring is actually slated for reuse, while 80 percent will be pulped. The Osaka Prefecture Lumber Federation explains that the problem lies with the structure's laminated wood construction, created by gluing together thin boards measuring only 42 centimeters on each side, which may not be sufficiently durable to last beyond the Expo period.
The site's future development plans add another layer of concern for architecture enthusiasts. Led by Osaka Prefectural and City Governments, an Integrated Resort project is exploring new uses including a 55-story tower, convention center, and casino. The prospect of this splendid architectural achievement being fed into wood chippers is only slightly less depressing than imagining trade fairs and gambling where visitors once enjoyed cool breezes and spectacular views.
More appealing alternatives would include retaining the structure as a public park or using it as the foundation for a new residential district, though these options appear economically and structurally unrealistic. The need to recoup a $1.65 billion expenditure likely made the City of Osaka's decision to sell the site—now enhanced with publicly financed infrastructure including a Chuo subway line extension—inevitable from the project's inception.
Architects designing for Expos clearly understand the temporary nature of their structures, though this knowledge hardly diminishes the disappointment of losing remarkable buildings like the Grand Ring. The energy expended and materials consumed for temporary construction raise serious questions about sustainability, despite organizers' environmental claims. Whether the architectural innovation achieved justifies the environmental cost remains debatable.
These concerns extend beyond individual projects to fundamental questions about the Expo model itself. The current approach, with its decades-old gestures toward sustainability, appears increasingly hollow and inadequate. Architects might better serve innovation through alternative models focusing on permanent structures or creative renovation of existing buildings rather than temporary spectacles.
Meanwhile, the Expo juggernaut continues its relentless advance toward the next iteration. The 2030 World Expo will take place in Saudi Arabia, with announcements proudly displayed in the country's current pavilion and promoted online. Plans promise vast territorial development using the most advanced environmentally friendly materials and technologies, backed by enormous national wealth suggesting unprecedented building scale.
The Saudi Expo will feature celebrated international architects realizing provocative designs, architectural representation from 195 countries, and an projected 40 million global visitors hoping to glimpse the future. In a world already confronting severe environmental and political challenges, this promises to be a particularly intense event by any measure, raising questions about whether the architectural community will continue supporting this increasingly problematic model of innovation and cultural exchange.
