Stargazing at Bisei: why is this Okayama town so dark?

Bisei, a town in Ibara City in western Okayama, is Asia’s first International Dark Sky Community (DarkSky International, 2021). You can stargaze there with your own eyes or through the 101 cm telescope at Bisei Astronomical Observatory, which is open to the public on Friday to Monday nights.

Why is Bisei good for stargazing?

It sits on the Kibi Plateau, known to astronomers for dark skies, a high rate of clear nights and steady air. Bisei passed Japan’s first light pollution prevention ordinance in November 1989, and all public outdoor lighting in the town has been replaced with fixtures that meet DarkSky’s standards.

What can you do at Bisei Astronomical Observatory?

• 101 cm telescope: night viewing of stars, planets and galaxies. The English page lists Friday, Saturday, Sunday and Monday nights.
• No booking needed except for groups or special programmes.
• Rainy nights: a 3D universe show (“4D2U”) on the first floor.
• Language: the observatory says its explanations are currently in Japanese only.

Opening times and fees can change; check the observatory’s Japanese site before you go.

How to prepare for stargazing at Bisei

Bisei is rural and hilly, so drive the route by daylight first if you can. The town has warm, low lighting on purpose; keep your headlights low and white torches off. Check the clouds and the Moon, and pack layers; the stargazing trip checklist has the full list.

Sky Map (my app) shows what is up tonight from Bisei and its Tonight’s Sky Conditions gives cloud cover, humidity and the best time.

Other dark-sky places in Japan: Ishigaki and Iriomote, Kozushima.

Sources: DarkSky International place page and 2021 announcement (darksky.org), Bisei Astronomical Observatory English pages (bao.city.ibara.okayama.jp), checked 2026-10-27.