Forests, or 'Woodlands', are collections of trees that can appear on the earth when there is sufficient nutrients, water, and sunlight. Very often they are in proximity to a . Forests in the world of Arda were wondrous and alive with many strange forms of life; life that more or less Sentient which in some ways could at times be dangerous. Forests corrupted by the dark forces like Mirkwood were even more dangerous and perilous, and contained many savage and unnatural creatures.