Monica
Hi, we are visiting Nagasaki via cruise in February. I would like to know if that is possible we can visit Unzen Onsen on the same day return. Our ship will be in port from 10am to 8pm on Feb 25. Thank you.
Akane
it will depend on the timing of the busses
maybe you can take a look at the bus schedule here http://unzen.org/e_ver/access/#sec3 and see if you can make it. The distance is only around 100 minutes
there is also these link, but it is in japanese:
https://www.keneibus.jp/local/express/unzen/
http://www.keneibus.jp/local/express/unzen/timetable_unzen_20170401.pdf
