The exhibition is really dated, most exhibits haven't been updated since the museum's opening in the early 1980s. (Sure, the facts displayed might not have changed, but the means to convey them have.) The entrance fee isn't exactly cheap; considering that, the overall experience is underwhelming. For people who don't read Japanese, it's hardly possible to follow. Not much explanation in English. While the website says there is a free audio guide (which we only noticed after our visit), we weren't offered one when we bought our tickets and there was no sign of an audio guide at the ticket counter. If you go to Mount Aso, you probably should visit the museum anyway. Try to get a guide in your language you're interested in the science part.