A lot of significance for the mountain comes from the fact that it’s where the boys keep the fire. The mountain contrasts greatly to the beach. The beach is for civil, and democratic rules, while the mountain is for savagery and wild behavior. For the first half of the novel, the mountain is where the boys keep the signal fire. As the highest point on the island, the mountain is their only chance of rescue. In the latter half of the novel, it becomes the dwelling of the beast (really a dead paratrooper), signifying the boys’ turn towards irrationality, savagery, and abandonment of civilization. The discovery of the “beast” on the mountaintop coincides with Jack’s attempted coup, and descent into madness. As a result, the mountain shifts from a symbol of survival and hope, to a symbol of fear.