Mt Aso, Kumamoto
Not far from Kumamoto is the real live active volcano, Mt. Aso, one of several on Kyushu. There are three main viewing areas. Scattered around the rim are mushroom shaped pill boxes so people can take cover from spewing ash and cinders when the volcano gets REALLY active. Mist and gas makes it a bit difficult to see the lava lake, but every once in a while the mist clears and you can get a clear look of the it. The smell of sulphur permeates the air all around the rim and you can buy bags of sulphur or figurines made from volcanic ash from various vendors.