Mount Ōkueyama, Sobo-Katamuki Quasi-National Park

Mount Ōkueyama, also known as Mount Ōkue, is a volcanic mountain on the Japanese island of Kyushu. Part of an ancient volcanic formation known as the Okueyama Volcano-plutonic Complex, Mount Ōkueyama experienced a massive eruption ~13.7 million years before present; it has been postulated that this eruption measured 8.0 on the Volcanic Explosivity Index, making the Ōkueyama eruption larger than any eruption in recorded history. The mountain is now considered to be extinct. ()