Aso-san is one of the world’s largest calderas. With a whopping diameter of 25km the dimensions are very impressive. Naka-dake, a vulcanic cone of Aso-san, continues to be active. Just recently he has again erupted, so the surrounding was currently closed for hikers. However the road to the volcanic museum was open and we made the 500m ascend to be rewarded with a remarkable view.