Tokyo · Kozushima Island
Bortle 2 · Pristine dark sky ｜ Elevation 80m ｜ SQM ~21.6 ｜ Best view South
An International Dark Sky Park in Tokyo’s island chain, often branded as a Dark Sky Island. Its distance from the metropolis and island-wide lighting work make it a strong Tokyo-based dark-sky trip.
🌌 Tonight the Milky Way core climbs to a shootable altitude around 20:42, sinks back near 02:02, and peaks around 22:32 at roughly 27° in the South.
Reach it by high-speed boat or ferry from Takeshiba, or by air from Chofu. Leave buffer for sea and flight disruptions.
Lodging, local guides and stargazing spots are available; a local tour is safer than exploring unfamiliar dark roads alone.
Spring through autumn for Milky Way and island skies; keep a weather backup because boats are weather-sensitive.
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