A metaphor re: life used by Dante in his Inferno. See Canto I. Related to all the trials and tribulations of life, it's passions, fears--also the state of Florence with the factions Guelf and Ghibelline.

See also Dante's Convito, IV. 25, where he says, "Thus the adolescent, who enters into the erroneous forest of this life, would not know how to keep the right way if he were not guided by his elders." Or Spenser, in his Faerie Queene, IV. ii. 45: "Seeking adventures in the salvage wood."

An Inferno note.