Photo/Illutration The Grand Ring of the Osaka Kansai Expo, certified by Guinness World Records as the world’s largest wooden architectural structure (Toshiyuki Hayashi)

OSAKA—A little over a month before its opening, the 2025 Osaka Kansai Expo is already making the records book. 

The Grand Ring of the world's fair was recognized as the “largest wooden architectural structure” in the world by Guinness World Records on March 4.

Designed to be the iconic architectural feature of the expo, the Grand Ring’s wooden roof covers an area of 61,035.55 square meters.

“After a rigorous evaluation, the structure was officially certified as a Guinness World Record,” an official Guinness adjudicator said that morning at the expo site on Yumeshima, an artificial island in Osaka’s Konohana Ward.

The official then presented the certificate to Hiroyuki Ishige, secretary-general of the Japan Association for the 2025 World Exposition, and Sosuke Fujimoto, who designed the venue and conceived of the Grand Ring.

“As the organizer, I am deeply honored and delighted,” Ishige said. “The ring is a remarkable structure that visually embodies the expo’s core theme of ‘Unity in Diversity.’”

“At a time when the world is at risk of division, I sincerely hope this ring will help bring people and nations together, inspiring a sense of global unity,” he added.

Construction of the Grand Ring began in June 2023 and was completed on Feb. 27, 2025. The project was led mainly by the construction firms Obayashi Corp., Shimizu Corp. and Takenaka Corp.

The ring stands 12 to 20 meters tall, is 30 meters wide and has an outer diameter of around 675 meters.

“We’ve been saying the full loop is about 2 kilometers, but at nearly 2,025 meters, its length is fitting for the 2025 Expo,” Ishige said.

Built at a cost of 34.4 billion yen ($230 million), the structure remains a topic of debate. Discussions about its significance and whether it should be preserved or repurposed after the event are ongoing.

The ring was originally set to be dismantled and its materials repurposed after the expo closes on Oct. 13. However, redevelopment plans for the site now include preserving part of the structure.

A final decision on whether to dismantle or retain it has yet to be made.

“Now that it’s completed, it truly is a remarkable structure,” Fujimoto said. “It would be a shame to tear it down, and if possible, I’d love for it to be preserved in its entirety.”

“Maintenance costs and future redevelopment plans make it a complicated issue, but if we can preserve as much of it as possible, that would be wonderful,” he added.

The Osaka Kansai Expo 2025 opens on April 13. 

Related News