This is the world's largest volcanic caldera, and despite the regular announcements of volcanic activity there are 10,000 people living within its rim. That alone makes it a fascinating place to visit, with the otherworldly feeling of climbing up over Nakadake crater rim in a cable car and seeing the sheer size of it. On its northern slope is Komezuka, a beautifully shaped volcanic cone in grassland that makes for a lovely walk with the opportunity to ride horses in the summer months. Since the authorities need to close the crater when the volcano is too active, the Japanese have come up with the ingenious Aso Super Ring - a 3D holographic experience that replicates the different landscapes of the crater. Not quite the real thing of course, but a brilliant technological venture that shows Japan is still at the cutting edge.
I can't think of anything that excites a greater sense of childlike wonder than to be in a country where you are ignorant of almost everything.Bill Bryson