I found a place that was advertised as the Grand Canyon of Japan. The reviews were all 5 stars, so we decided to take the 3 hour bus ride (one way) to the gorge. I heard it was small, and it was, but I think it was worth doing once. We rented a row boat and paddled up and down the gorge including past some waterfalls. We ate lunch at a place that slides noodles down a bamboo water chute and you need to catch them with your chopsticks. We opted to just have them served to us normally given our lack of skills with chopsticks and not really understanding what that option was about. We then proceeded to hike a trail following the river that runs through the gorge. The trail then split off and lead to a shrine with giant ancient cedar trees. The three hour bus ride back to Kumamoto ended our tiresome, but good day.