恵庭岳、支笏湖北岸に聳える活火山

約4万年前に形成された支笏カルデラを囲む外輪山の一つ。名前の由来をアイヌ語「エエンイワ」（頭が尖っている山）に持ち、その名の通り山体は溶岩円頂丘と溶岩流から構成され、脆く急峻な地形。活火山で、現在も登山道下に噴煙が上がる。山体崩落のため山頂までの登山道は無く、バリエーションルートによってのみ登頂可能。

Mt Eniwa, an active volcano rising on the northern shore of Lake Shikotsu

It is one of the outer rim mountains surrounding the Shikotsu caldera, which was formed about 40,000 years ago. The name comes from the Ainu word “een-iwa” (mountain with a pointed head), and as the name implies, the mountain body is composed of lava cirques and lava flows, and the terrain is brittle and steep. It is an active volcano, and even today, plumes of smoke can be seen below the mountain trail. Due to a collapse of the mountain body, there is no trail to the summit, and the summit can only be reached by a variation route.