Grand Ring 'symbol of unity'

Striking: Despite criticism and cost overruns architect stands by his work

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, its creator says.

The 2km-circumference of Sou Fujimoto's striking structure will surround dozens of national pavilions at the six-month event from April.

World Expo, held every five years in different locations, allows participating countries to show off their technological and cultural strengths.

Organisers have struggled to rouse enthusiasm for the 2025 event, facing slow ticket sales and public concern over the ballooning construction budget.

But Fujimoto, one of Japan's top architects, said there is a deeper value to the 34.4 billion yen (about R4.1 billion) Grand Ring than just its price tag.

The Expo is a "really beautiful, precious opportunity where so many different cultures... and countries come together in one place to create diversity and unity", the 53-year-old said under the Ring's imposing latticed beams.