Kumamoto Prefecture (熊本県, Kumamoto-ken) is a great place to go to if you’re looking for hot springs; they’re everywhere, including the popular Kurokawa Onsen. Be sure to visit Kumamoto Castle, one of Japan’s top castles, while you’re there as well.
If you like nature, Kumamoto is also a nice destination; Suizenji Park is perfect for photographs, while Mount Aso is one of the world's largest active volcanoes. Take a look at the unique Tsujun Bridge for some architectural magnificence.
One popular activity in Kumamoto is riding the scenic Steam Locomotive Hitoyoshi; make sure you get reserve seats well in advance, as tickets sell out surprisingly quickly. Kumamoto is also famous for its raw horse sashimi; if you can't muster up the courage to try that, have some tonkotsu (pork-bone broth) noodles instead.
Over 66,000 purple irises in several varieties bloom in the Takaseura River in late May to early June during the Tamana Iris F..
The town of Arao holds a rice planting festival to kick off the start of the annual growing season.