In "Lord of the Flies" the jungle is the antithesis of the beach with regard to the fire. While the fire runs rampant in the jungle and destorys everything in its path, Ralph urges the boys to keep the fire burning on the beach where the huts are built so that they be rescued; he also suggests that the littl'uns use a part of the beach as a latrine so that the waves can cleanse the island of this waste. In other words, the beach represents a fresher, more civilized area while the jungle signifies the savagery of the boys who defecate at will like wild animals and the hunters walk around this as they seek the feral pigs.
It is into the forest that Simon, turning his "back on the others, walked with an air of purpose" (Chapter 3), and it is in in the jungle that the "beast" resides, whether it be in the form of the parachutist or the pigs-head, dripping blood and covered with devilish flies. As Simon sits in the screen of leaves that the jungle affords him,
Darkness poured out, sumerging the ways between the trees till they were dim and strange as the bottom of the sea..Their scent spille out into the air and took possession the island" (Chapter 3).
Just as the the fragrance from the jungle overtakes the island, so, too, does the evil inherent in it. In the jungle, Jack and the others liberate themselves "from shame and self-consciousness" behind masks.
The thicket on the mountain is referred to as the "unfriendly side of the mountain. where "Passions beat about Simon on the mountain-top with awful wings." It is on this "awful mountain-top that Simon and Piggy are murdered. And, it is in the "darkness of this island" that Ralph must hide in an effort to save himself from Roger "who carried death in his hands" (Chapter 12).