Tawarayama, in the Minami Aso area, is one of the most popular day hikes in Kumamoto. A trail winds straight up the hill past energy-harnessing windmills before flattening out on a grassy plain. It then meanders through an oak and pine forest before one final steep slope brings hikers out on the summit of Tawarayama. On a clear day, the five peaks of the Aso region are clearly visible just across the valley; if you're lucky, you can also catch the far-off peaks of Unzen across the bay in Nagasaki Prefecture. The hike has some tough sections but at three hours round trip, it's more than doable for anyone in decent shape with a good pair of shoes.