Inakahama is a long, gently curving beach on Yakushima's south coast, and one of the most important sea turtle nesting sites in Japan. Loggerhead turtles (akaumigame) come ashore here from May to July to lay eggs, and hatchlings emerge and scramble to the sea between July and October. Organised night-watching excursions run during the nesting season — you wait in the dunes with a guide until a female drags herself up the beach.
Outside turtle season, the beach is pleasant for swimming and the water is clear. The beach is backed by a thin line of coconut palms and casuarina trees, giving it a tropical feel unusual in Japan. Access is by road from Yakusugi Land direction; the beach car park is signposted. Note that during turtle season, entering the beach after dark requires a licensed guide and separate tickets — independent night visits are prohibited to protect the turtles.