万倉の大岩郷

Mangura no Daiiwa-go is a geological formation in Yamaguchi Prefecture composed of massive boulders scattered across an area about 110 meters long and 40 meters wide. The individual stones range from 1 to 6 meters in diameter and are made of quartz diorite rock.

The rock formations developed during the period from the Pleistocene through the late Yayoi era and received national natural monument status in December 1935. This designation recognized the site as an important example of natural rock formation development in Japan.

The site serves as an educational center where students and researchers study geological processes and natural rock formation patterns.

Visitors can reach the site by public transportation or private vehicle, with hiking trails weaving between and across the large stones. The uneven terrain requires appropriate footwear and care when exploring the location.

Among the stones live rare ferns like Crypsinus hastatus and rare orchids such as Bulbophyllum inconspicuum that have adapted to the rocky setting. These plant species make the site a valuable habitat for specialized vegetation.

GPS coordinates: 34.13283,131.23589

Latest update: December 14, 2025 16:47