Shiraho Reef runs along the southeast coast of Ishigaki near the small fishing village of the same name. It holds one of the largest concentrations of blue coral (Heliopora coerulea) in the world — a rare species that grows far more slowly than most reef-building corals and is consequently very difficult to restore once damaged. The reef is also home to staghorn corals, sea turtles, and a dense population of reef fish.
Snorkelling is possible from the beach at Shiraho village, though the reef is at its best a little offshore. Local dive operators run trips specifically to Shiraho, and serious divers tend to rate it above the more visited sites nearer Ishigaki town. The village itself is quiet, traditional, and largely untouched by tourist development — a different experience from the busier northern coast.