Guide
The Yakubashiri Lava Flow, located in Hachimantai City, Iwate Prefecture, is a geological formation created by the solidified lava from the 1732 eruption of Mt. Iwate. The area covers approximately 149.63 hectares, with a length of 3–4 km and a maximum width of 1–1.5 km. Because the terrain has remained largely unchanged for nearly 300 years, it is designated as a National Special Natural Monument. It is also part of the Towada-Hachimantai National Park's Special Protection Zone, making it a premier site for observing the effects of volcanic activity on the landscape.
This landscape was shaped by the massive eruption of Mt. Iwigate in 1732. The way the lava flowed and solidified in its current form created the distinctive dark-brown terrain seen today. The site was designated as a National Special Natural Monument in 1952 and added to the Special Protection Zone of Towada-Hachimantai National Park in 1957. Because vegetation recovery is extremely slow in this volcanic environment, it serves as an invaluable scientific site for observing the ongoing evolution of volcanic landscapes.
The most striking view is the contrast between the dark-brown lava flow and the majestic peak of Mt. Iwate (2,038m). A 2km nature observation trail is available, allowing visitors to get a close-up look at the volcanic topography. Near the first vent site (elevation 1,220m), the area is known as one of Japan's largest habitats for the Komakusa (Dicentra peregrina) flower. In early summer, you can see these beautiful pink flowers blooming along the trails. Additionally, the adjacent larch forests feature accessible, barrier-free paths, making it easy to enjoy the forest scenery.
The Yakubashiri Lava Flow is inaccessible during the winter months (roughly December to May) due to heavy snow. The best time to visit is during May and June when plant life is most active. Early summer is particularly special as the