noun
sea of trees; dense forest expanse
Evokes a vast, unbroken stretch of forest, often with a poetic or slightly ominous feel. Frequently associated with Aokigahara (青木ヶ原樹海).
富士山の麓には広大な樹海が広がっている。
A vast sea of trees spreads out at the foot of Mount Fuji.
樹海の中では方向感覚を失いやすい。
It's easy to lose your sense of direction in a sea of trees.