Ōnogame
Ōnogame, “the great turtle,” is an enormous rock that juts out of the sea near the northern tip of Sado Island. The headland monolith is a single massive slab of dolerite that rises 167 meters from the water. It is the largest geological feature of its kind on Sado. Visitors can admire its profile from the adjacent park or hike the dirt path to the top (a climb of about 30 minutes) for an unmatched view of the coastline and surrounding waters. Less arduous walking paths start at Ōnogame’s base and lead along the nearby cliffs.
Ōnogame was created around 20 million years ago. Deep below the ground, a pocket of magma formed, cooled, and was gradually pushed to the surface by tectonic activity. The igneous rock was then slowly exposed by erosion, leaving a monolith that has been an object of veneration for millennia. The name “Ōnogame” contains the word for “turtle” (kame), but it may originally derive from the Ainu word for “god” (kamui). Some experts believe Sado’s prehistoric inhabitants traded beads and other goods with indigenous Ainu people from the mainland, and the rock’s name is thought to support that theory.
The area around Ōnogame is known for the dense fields of yellow-orange Amur daylilies (Hemerocallis middendorffii var.) that bloom on its slopes from late May until early June. The Sado Kanzō Festival, held nearby on the second Sunday of June each year, features folksongs and ondeko drumming by dancing, demon-masked performers.