Rurikei
This ravine is four kilometers long and is located on a 500-meter-high plateau in the south-west of Sonobe-cho, Nantan City. The clear stream that runs from Tsuten Lake reflects sunlight and glitters a lapis lazuli blue, hence the name. The clear stream and surrounding forest are ideal for hiking. There are also prepared walking paths available, bringing in many visitors from inside and outside the prefecture. The autumn changing leaves season is particularly recommended.