Why This Remote Japanese Island Is a Stargazer's Dream
Ishigaki offers dark skies, firefly watching, and other nocturnal wonders. Here’s how to make the most of it at night.
With its secluded, white-sand beaches, vibrant coral reefs, and world-renowned manta ray diving, Ishigaki is an idyllic ocean retreat. Home to the city of Ishigaki, the southernmost in Japan, the 85-square-mile island is part of Okinawa Prefecture, sometimes referred to as the Hawaii of Japan, and sits at the same latitude as Taipei. Reachable via a three-and-a-half-hour direct flight from Tokyo, it can be a destination unto itself or a jumping-off point to explore the rest of the remote Yaeyama Islands.
Yet many of the island’s natural wonders can be experienced only after dark. Iriomote-Ishigaki National Park, which encompasses part of Ishigaki and several of the neighboring islands, has been recognized by DarkSky International as Japan’s first certified International Dark Sky Place for its exceptional stargazing. It’s also a haven for other phenomena, including rare fireflies, cat-sized coconut crabs, and the Sagaribana, a fuzzy flower that blooms after sundown one night a year.
Twilight outings are woven into local culture. “In Yaeyama, people have long used the movement of the stars as a guide for the timing of agricultural work, and songs and stories related to the stars have been passed down,” says Shuhei Watanuki, the operations manager at the Yaeyama Visitors Bureau.
Here’s how to experience the best of Ishigaki after dark.
Many Choices for Stargazing
In recent years, astrotourism has been soaring in popularity, as travelers visit remote corners of the planet to admire starlit skies. In 2018, the nonprofit DarkSkyInternational, which has certified more than 250 stargazing-friendly sites around the world, gave Iriomote-Ishigaki National Park tentative dark-sky status. This year, following efforts to retrofit exterior lighting in populated areas to reduce light pollution, the park earned official recognition.
Ishigaki’s location allows stargazers to view constellations in both hemispheres. Visitors may see the north star, the southern cross, and 84 of the 88 constellations officially recognized by the International Astronomical Union. The Milky Way is visible year-round, though its bright core is most prominent from spring through fall.
In August, the annual Southern Island Star Festival brings music, cultural events, and interactive stargazing to Ishigaki. Throughout the year, Ishigakijima Astronomical Observatory hosts visitors at its site perched more than 600 feet above sea level atop Mount Maesedake. Hotels such as the waterfront ANA Intercontinental Ishigaki Resort also host their own astronomical tours.
Travelers can stargaze on their own, too; some of the best locations are Banna Park, Kabira Bay, and the remote Hirakubo Peninsula in the north. Here, “you won’t hear any sounds of daily life like cars, you only hear the sounds of insects and waves,” says Yuya Tanaka, a manager at Ishigaki Adventure PiPi, an outfitter that runs year-round stargazing tours.
Expert-led trips come with additional benefits. Many guides have learned about the cultural history of the constellations by attending the Ishigaki Island Churaboshi Meister Training Course, says Watanuki, and can tell guests star stories that have been passed down through generations.
The Dance of the Fireflies
Reducing artificial light matters for reasons beyond preserving the majesty of the night sky. Many animals, such as fireflies, rely on darkness to communicate and mate. At least 20 percent of the world’s studied fireflies face the threat of extinction due to light pollution and climate change.
These are important concerns on Ishigaki, one of the few habitats for the Yaeyama Hime firefly. Spring, says Tanaka, “is the magical season when the Yaeyama Hime fireflies, one of Japan’s smallest firefly species, glow all at once.” Her company offers guided trips to see the golden-tinged insects blink in unison.
The population is most abundant in the island’s dense, subtropical rainforest, especially near the trailhead to Mount Omoto. The fireflies often emerge just after sunset, so it’s best to arrive while it’s still light out. March through May are the best viewing months.
A Phantom Flower
Summer, before the peak of typhoon season from August through September, is among Ishigaki’s busiest travel periods. It’s also the time of Ishigaki's most elusive nocturnal phenomenon: the Sagaribana tree in bloom.
This evergreen, which also grows in Polynesia and South Africa, is known as the powderpuff tree for its fuzzy, pastel-pink blossoms. These “phantom flowers” appear for only one night a year after the sun sets, emitting a vanilla scent, then wilt by morning. The best way to see them is on a nighttime mangrove tour in June or July. Sagaribana trees will blossom intermittently over a period of about 10 days.
Colossal Crabs
The warm summer months are also prime time to see Ishigaki’s famed bird-eating coconut crabs. These colossal arthropods, which can reach the size of a cat with leg spans of more than three feet, are the largest land-dwelling crabs in the world. They’re most visible on Ishigaki from July through August, the peak of their spawning season.
A nighttime jungle safari with an expert guide is the safest way to spot the animals, whose pinch force, according to researchers, is stronger than the bite of lions and leopards. They inhabit forested terrain favored by the venomous Habu snake, so boots are recommended for safety; many outfitters provide them.
After-dark outings also present an opportunity to see some of the island’s other nocturnal inhabitants, like owls and fruit bats, along with countless stars on a clear night.
