Hoshizuna, on the northern coast near Uehara, is the most accessible of Iriomote's beaches and famous for the star-shaped grains of sand mixed into the white coral debris. Press a wet palm into the surface and shake it off, and a handful of little white stars will cling to your skin.
The lagoon offshore is shallow and protected, with a fringing reef good for an easy snorkel. There are showers, a small café, and gear rental in the high season. Strong currents past the reef edge make it sensible to stay within the swimming markers.