Nagano · Achi Village
Bortle 3 · Rural dark sky ｜ Elevation 1400m ｜ SQM ~21.4 ｜ Best view South
A signature astrotourism village in southern Nagano. Japan’s Ministry of the Environment ranked Achi first in its 2006 nationwide star-watching survey, and the Heavens Sonohara night ropeway climbs to an alpine field around 1,400 m.
🌌 Tonight the Milky Way core climbs to a shootable altitude around 20:55, sinks back near 02:05, and peaks around 22:45 at roughly 26° in the South.
Most visitors base around Hirugami Onsen and the Heavens Sonohara night tour. Check ropeway dates, booking rules and operating status before going.
Strong visitor infrastructure: onsen lodging, guided night programs and ropeway access. Independent late-night observing sites should be checked separately.
Late spring through autumn is best for Milky Way and highland stargazing; winter can be transparent but requires road and opening checks.
See the nearby city's stargazing calendar
Bortle class and SQM are estimates for well-known sites, used to compare darkness — not on-site measurements.
Related tools: Taiwan Dark-Sky Map · Stargazing & Moon Viewing Score · Meteor Showers