also Mount Kita Yoko, is an active lava dome

Lava dome

|250px|thumb|right|Image of the [[rhyolitic]] lava dome of [[Chaitén Volcano]] during its 2008–2009 eruption.In volcanology, a lava dome is a roughly circular mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano...

 located in the Northern Yatsugatake Volcanic Group

Northern Yatsugatake Volcanic Group

, also just Kita Yatsugatake is a volcanic group of stratovolcanoes and lava domes located in Nagano Prefecture on Honshū in Japan.-Description:...

 of the Yatsugatake Mountains

Yatsugatake Mountains

The Yatsugatake Mountains are a volcanic mountain range on the border between Nagano Prefecture and Yamanashi Prefecture on the island of Honshū in Japan.-Description:...

, Honshū

Honshu

is the largest island of Japan. The nation's main island, it is south of Hokkaido across the Tsugaru Strait, north of Shikoku across the Inland Sea, and northeast of Kyushu across the Kanmon Strait...

, Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

. Mount Yoko has shown the most recent activity and is now considered an active volcano. It last erupted about 800 years ago. The eruption consisted of ash with a lava flow of some 3 million cubic meters. The eruption was dated by corrected radiocarbon dating. The next previous eruption was in or after 400 BCE.