OSAKA, Japan — The Grand Ring, a symbol of the World Expo 2025 scheduled to take place in Osaka, Japan, next year, will be one of the largest wooden structures on earth. Much of the material going into this massive construction comes from lumber harvested in coastal Fukushima Prefecture, hit hard by the March 2011 earthquake, tsunami, and nuclear disaster. 

Another large portion of the wood is locally constructed Glulam mass timber products.

The Japan Association for the 2025 World Exposition announced in August 2024, that the wooden structure of the Grand Ring was completed with the installation of the Sky Walk ramps, connecting the entire 2km circumference into one complete ring.

The Grand Ring, conceived by architect FUJIMOTO Sou, the Expo Site Design Producer, is the symbol of the venue that represents the venue’s design philosophy of ‘Unity in Diversity.’ Assembly began on June 30, 2023, and construction has been progressing ever since.

Work will continue towards the opening of the Expo in April 2025, including the installation of elevators, escalators, and rooftop greenery.

It measures 20 meters high and 2 kilometers in circumference and the Grand Ring contains 27,000 cubic meters of wood. It is constructed using modern construction methods in addition to the traditional timber joints used in the construction of Japanese shrines and temples. It will be used as the main route of flow around the venue, providing smooth movement for crowds as well as a comfortable space to stay out of the rain, wind, and sun.

From the rooftop of the Grand Ring, the entire venue can be viewed from various points, and if you look outside the ring, visitors can enjoy the charms of the Expo site surrounded by sea and sky, such as the rich nature of the Seto Inland Sea, the spectacle of the setting sun, and the city of Osaka.

"The construction of the wooden building part of the Grand Ring, which began in June 2023, has been completed and connected to form a continuous ring. The Grand Ring is an architectural symbol of the Expo site’s concept of 'Unity in Diversity.' We are confident that visitors from all over the world will enjoy the Expo," said Tokura Masakazu, chairperson of Japan Association for the 2025 World Exposition.

• Timber used: (Domestic) Japanese cedar and Japanese cypress; (Foreign) Scots Pine
• Building Area: Approx. 60,000m2
• Inner Diameter: Approx. 615ｍ  Outer Diameter: Approx. 675ｍ
• Width: 30m
• Height: 12m (External height: 20ｍ The height of the skywalk that visitors can walk on.)

Of the 27,000 cubic meters of wood, 4,500 cubic meters of glued-laminated timber, or “glulam,” was supplied by Woodcore, a company based in Namie, Fukushima. The meltdown at the Fukushima Daiichi Nuclear Power Station triggered by the massive 2011 earthquake and tsunami hit the neighboring town hard, forcing all residents to evacuate. 

According to Nippon.com, Woodcore was established in 2018, in a partnership between Namie-based Asada Timber and Tōju Sangyō, a laminate manufacturer based in Kōriyama, also in Fukushima. Woodcore has been contracted to operate the Fukushima Laminated-Timber Advanced Manufacturing Center (FLAM), which was opened by the Namie government, and is the most advanced facility of its type in Japan.