Day trip from Kumamoto to Takachiho or Mt Aso

Hello... I am planning a day trip to either Takachiho or Mt Aso. I have tried to book a combined day tour to both places but unfortunately, it's not available for the date I have planned.

As I'll be travelling solo, I may have to rely on public transportation as i don't plan to rent a car. If i can only travel to one spot, which is better - Takachiho or Mt Aso? I'm a nature person - not so much interested in visiting shrines. And I'm likely going to visit Sakurajima when I'm in Kagoshima.

Any advice would be appreciated.

Thanks,
mungo

As much as I love Takachiho, a day trip to Takachiho on a public transport will put you on the bus for over 5 hours. If you don't mind that, I would certainly recommend Takachiho over Aso.

Both of these places are some of my favorite places in Japan. However - both are not that "public transport friendly' for day trips.

There seems to be buses from Kumamoto Station but this takes around 3 hours one way. Many of the shrines are spread over a fair distance - but at least there are some sites close to one another. It would be a really long day and I'm not sure it would be worth it - unless you spend the night. A bus tour might change my mind though.

https://www.japan-guide.com/community/mfedley/report-2894

Mt Aso is an amazing place to visit but it's really about the driving experience. There are many sites to see - but they tend to be spread out over long distances. If I had my own car for the day I'd choose Aso over Takachiho - but it would be a tough decision. Without a car - it's not worth it. My mind may change if it's on a bus tour.

https://www.japan-guide.com/community/mfedley/report-3333
https://www.japan-guide.com/community/mfedley/report-3334