Japan's Crown Prince and Princess Akishino have visited the venue of the upcoming expo in Osaka, western Japan.



The couple on Wednesday observed the site of Expo 2025 Osaka, Kansai, Japan, which opens on April 13 and runs for six months. The Crown Prince is the event's honorary president.



The couple went up to the 12-meter-high Skywalk on the roof of the Grand Ring, the expo's symbol.



They were briefed by an official from the Japan Association for the 2025 World Exposition on the ring, which has a circumference of 2 kilometers and is called "the world's largest wooden architectural structure."



They were told the structure was built using traditional methods for constructing Japanese shrines and temples.



The Crown Prince and Princess also visited the Japanese government's Japan Pavilion, and a facility sponsored by Osaka Prefecture and City.



In the center of the pavilion, a circular structure based on the concept of "cycle," is a 19-meter-diameter basin filled with water generated through biogas power generation. The couple asked the head of the pavilion about the system and mentioned the sound of the water.



They will attend the expo's opening ceremony on April 12 with Emperor Naruhito and Empress Masako.



The expo will be held on the artificial island Yumeshima in Osaka Bay, with 158 countries and regions expected to take part.