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remote mountain; mountain recesses
奥山に分け入ると人里の音が消えた。
When we ventured deep into the remote mountains, the sounds of civilization vanished.
熊が出没する奥山への立ち入りは危険だ。
Entering the remote mountains where bears roam is dangerous.
奥山で採れた薬草が高値で売られた。
Medicinal herbs gathered in the remote mountains were sold at high prices.