The coast of the Ariake Sea is an immense tidal flat, giving rise to an incredible sight at low tide. In the muddy mixture of sand and ashes left by former eruptions of Mount Aso, mutsugoro (mud hoppers) put on an amazing show, whilst contributing to the ecosystem of the mud by bringing the oxygen which it lacks. From the observation centre, equipped with binoculars, enjoy the view and admire the numerous species that live in this bay.