This video, titled "From Deep in Mt. Hotaka to Gendarmes｜Changing Gears After Witnessing a Rockslide｜Uma No Se Round Trip Video" (奥穂高からジャンダルム 滑落みて馬の背ピストンへ変更 馬の背詳細往復動画), was released by "Biryu Jr."

Mt. Hotaka is a 3,190m tall mountain in Chubusangaku National Park, which is centered on the Hida Mountains and straddles Nagano, Gifu, Toyama, and Niigata Prefectures.
It is the third highest peak in Japan and one of the 100 most famous mountains in Japan.
There is a route called "Uma no Se" (Horses Back) on Mt. Hotaka, and it is a very dangerous place to go through, there's only loose stones and not enough space to walk.
The videos shows a view deep in Mt. Hotaka, so if you enjoy mountain climbing, be sure to check it out.