A wave-shaped rock surrounding Aoshima Island, which has a circumference of 860 meters.
The mountain, which is composed of alternating layers of sandstone and mudstone (the Aburatsu Formation), was submerged by the sea and eroded by waves, resulting in the formation of a slight rise, known as an uplifted wave-cut plateau.
The regularly overlapping strata are gently sloping and have been eroded into a staircase-like formation, which is called the “devil’s washboard (rock)” because it looks like a giant washboard.
They can be seen along an approximately 8-km stretch of coastline from Aoshima Island to Kinshima Island in the south.
The Kuroshio Current flows from southwest to northeast along the southern coast of Miyazaki Prefecture, while the coastal current flows from north to south along the northern coast.
Because of its unusual topography, Aoshima is designated as a national natural monument as “Aoshima’s Rising Sea Bed and Oddly-shaped Wave Erosion Scar.
15 minutes on foot from Aoshima Station