Rosita Cipolla Star-shaped grains on Japan’s Hoshizuna Beach turn Iriomote Island into a natural planetarium, but these fragile wonders—and the island’s rare wildlife—need careful, respectful visitors.
There’s a remote corner of Japan where you can literally stroll over galaxies made of sand. Hoshizuna Beach on Iriomote—Okinawa Prefecture’s second-largest island—has become legendary because every tiny grain seems to mimic the night sky. Islanders affectionately call it “Hoshizuna-no-Hama” (“star-shaped sand”), and word of mouth has turned a once-sleepy shoreline into a bucket-list stop for travelers in search of the extraordinary.
The science behind the “star sand”
The beach’s “sand” isn’t sand at all. Each minuscule star is the vacant exoskeleton of Baculogypsina sphaerulata, a foraminiferan protozoan. These five- or six-pointed creatures measure barely 0.08 in (2 mm) across and cling to ocean algae throughout the Pacific. When they die, currents sweep their calcium-carbonate shells ashore, where they mingle with ordinary sand and pebbles to create a celestial carpet beneath your feet.
Una spiaggia di stelle ☆. Meraviglia di conchiglie a Okinawa, a 「星砂の浜」 /Hoshizuna no hama/. Uno spettacolo a dir poco meraviglioso~♥
Posted by Giappone Mon Amour on Thursday, September 9, 2021
Where else to find these tiny constellations
While Hoshizuna is the headline act, you can spot the same star grains on parts of nearby Taketomi Island. Local signs politely point out the phenomenon—another reminder that the Yaeyama archipelago hides more natural curiosities than most guidebooks can fit.
How to get there
Reach Iriomote by daily ferry from Ishigaki, hub of the Yaeyama Islands. Once docked, buses cover the coastline, but renting a scooter, bicycle, or compact car offers the freedom to chase every hidden cove.
Timing your visit
Aim for April–October when skies are clear, seas transparent, and typhoons haven’t yet unsettled the South China Sea. Do keep an eye on storm forecasts between June and September, the peak of cyclone season.
A fragile wonder: please look, don’t take
Iriomote also shelters the elusive Iriomote cat, a feline so rare that many locals have never glimpsed it. That rarity underscores a larger truth: Hoshizuna’s star sand is part of a delicate ecosystem. Removing even a handful is both illegal and, frankly, a theft from future visitors. Every tourist who pockets a souvenir leaves a subtle scar on a landscape that took millennia to form.
