Agatsuma Gorge

 is a two to three kilometer long ravine on the upper and middle reaches of the Agatsuma River in the towns of Highashiagatsuma and Naganohara, Gunma Prefecture, Japan. It has been designated a National Place of Scenic Beauty since 1935.
Overview.
The Agatsuma River flows through western Gunma Prefecture, crossing into Gunma via the Torii Pass from Nagano Prefecture and flowing eastward to join the Tone River at Saibukawa. A portion of the river passes through an area of eroded Miocene andesite and tuff breccia, forming a narrow ravine. The difference in height of the old route of Japan National Route 145 and the river surface is 50 meters. The river is curved and has a variety of landscapes such as pools, waterfalls, and strangely shaped rock formations. Surrounded by deciduous broad-leaved forests, it is a famous spot for viewing autumn leaves. In addition, natural concentrations of azaleas flowers in spring draw many visitors. 
Before the modern period, the Agatsuma Gorge was isolated and had very few visitors. A road was first opened in 1895, and afterwards the JR East Agatsuma Line provided rail service.