ITS creator says that a towering wooden 'Grand Ring' built for Expo 2025 in Osaka pays homage to Japan's architectural history and is a symbol of unity despite criticism over costs. The 2-kilometer (1.2-mile) circumference of Sou Fujimoto's striking structure will surround dozens of national pavilions at the six-monthlong event from April.

World Expo, held every five years in different locations, allows participating countries to show off their technological and cultural strengths. Organizers have struggled to rouse enthusiasm for the 2025 event, facing slow ticket sales and public concern over the ballooning construction budget.