Collocations for forest - noun

dense, thick | impenetrable | dark | native, natural | ancient, primeval, virgin | rain (also ‘rainforest’), tropical | coniferous, deciduous | beech, birch, pine, etc.

stretch, tract
a large stretch of virgin forest

plant | chop down, clear, cut down, destroy
Forest is being cleared to make way for new farming land.

be covered by/in/with
Much of Europe was once covered in forest.

stretch
Thick forest stretched as far as the eye could see.

tree | floor | land | fire

in a/the ~
They got lost in the forest.

through a/the ~
We slashed our way through the dense forest.

the edge/heart/middle of the forest