【Hida City, Gifu Prefecture】Challenging Einstein's Last Homework: "KAGRA Public Opening 2026" to be Held on Saturday, June 20! Tour the 3km L-shaped Large-scale Cryogenic Gravitational Wave Telescope 200m Underground

Hida City, Gifu Prefecture (Mayor: Junya Totsuka) and the Institute for Cosmic Ray Research, University of Tokyo, will hold a public opening of "KAGRA," the world's most advanced gravitational wave observation facility located deep underground in the Kamioka Mine, on Saturday, June 20, 2026. This is a valuable opportunity to receive direct explanations from researchers in a normally restricted research area.

Experience the Giant 3km Arm! KAGRA, the World's Most Advanced Large-scale Cryogenic Gravitational Wave Telescope

Approximately 200m underground in Kamioka-cho, Hida City, Gifu Prefecture, lies KAGRA, Japan's world-renowned large-scale cryogenic gravitational wave telescope.

Gravitational waves are ripples in spacetime itself, transmitted by large-scale cosmic phenomena such as the merger of black holes and neutron stars. Their existence was predicted by Albert Einstein 110 years ago, and their first observation in 2015 garnered significant attention. Observing gravitational waves is expected to reveal cosmic events previously undetectable by light, greatly advancing our understanding of the universe.

KAGRA is a world-leading device with giant L-shaped arms, each 3km long, that observes by cooling sapphire mirrors to extremely low temperatures. This event offers a special public viewing inside the facility, filled with human ingenuity, to unravel the mysteries of the universe that cannot be captured by light.

Event Overview

This is a tour-style event where participants can walk approximately 2km (about 1 hour round trip) inside the underground facility while listening to direct explanations from active researchers.

- ◇Date Saturday, June 20, 2026

- ◇Location "KAGRA Underground Research Facility" in Kamioka-cho, Hida City, Gifu Prefecture

- ◇Meeting Place Roadside Station Skydome Kamioka (6 Yuhiyagaoka, Kamioka-cho, Hida City, Gifu Prefecture)

- ◇Participation Fee 2,000 yen

- ◇Capacity 200 people (150 national slots / 50 Hida citizen slots)

- ◇Eligibility Elementary school students and older (minors must be accompanied by a guardian; the representative must be 18 years or older) who can walk approximately 2km round trip.