Achi Village Namiai Park - The Best Starry Sky in Japan Certified by the Ministry of Environment

Overview

Achi Village is located at the southern edge of Nagano Prefecture in the southern Shinano region, nestled in mountainous terrain. In a nationwide starlight observation survey conducted by Japan's Ministry of Environment in 2006, it was ranked first as "the best place for observing the night sky," earning the village its reputation as home to Japan's most beautiful starry sky.

Namiai Park is a dedicated stargazing observation facility in Achi Village, equipped with a dedicated observation deck and guided tours that allow anyone to easily enjoy the best starry experience.

Observation Environment

The primary reason Achi Village was chosen as having Japan's first-class starry sky is its basin-shaped geography surrounded by mountains on all sides. The surrounding mountain ranges effectively block light pollution from nearby cities, and above your head stretches a pitch-black sky corresponding to Bortle scale class 1.

From Namiai Park at approximately 1,200 meters elevation, on nights with good conditions, the number of stars visible to the naked eye reaches several thousand. The Milky Way appears less as a bright band and more as a dense collection of faint stars, allowing you to feel its structure even without optical aids.

Facilities and Usage Information

Namiai Park features wood deck observation areas with rental telescopes and binoculars available. There are also hammock areas where you can recline and gaze at the stars for a more relaxed stargazing experience.

Guided tours by stargazing experts are perfect for beginners, teaching you how to find seasonal constellations and celestial objects. The on-site café serves warm beverages.

Since reservations are required, advance booking through the official website is necessary. During summer vacation and holidays, the park can become crowded, so early reservation is recommended.

Access

Approximately 20-30 minutes by car from Sonohara IC on the Chuo Expressway. From the Nagoya area, it takes about 1.5 hours; from Tokyo, about 3.5 hours. Public transportation access is limited, so visiting by car is the standard option.

Observation Tips

Clear nights around the new moon are ideal. Confirm the moon phase and weather forecast on the official website before deciding when to visit for the best experience. Even in summer, nights can be cool, so bring a long-sleeved jacket.