Why is the beach an important symbol and what does it represent in Lord of the Flies?

In Lord of the Flies, the reader is introduced to Ralph and Piggy as they climb through creepers and tree branches until they can reach the shore of the lagoon. From there, they can survey the area and the narrator notes that the beach is "endless apparently." Behind the boys lies "the darkness of the forest" creating a stark contrast with the "bright" beach where Ralph "swept a double armful of sand...with bright, excited eyes." The beach therefore has the capacity to symbolize the endless possibilities or infinite potential of the island. The beach is between the sea from which rescue will come and the forest and jungle which hold many shadows and secrets and which will ultimately create an irrational fear of the beast in the boys.

When Ralph blows the conch for the first time, the boys congregate on the beach and it is interesting that Jack's party of boys is described as "a creature" as they (it) emerge(s) from "mirage onto clear sand." It is as if, away from the beach, Jack and his hunters can transform themselves but the beach exposes them for what they are, which is just a group of choir boys.  

The beach is one of the settings in the story along with the forest and jungle, the mountain and Castle Rock. Each of these has a unique backdrop which is significant and contributes to the understanding and flow of the story. The conch shell is found in the water at the beach and therefore ties the beach to its own symbolism as it represents good order and democracy. The boys build shelters on the beach and chapter 3 is entitled "Huts on the Beach." The shelters give the boys a feeling of "Home" and the beach and the swimming create unity rather than division and are "just sufficient to being them together again." Later, Jack will form his own separate tribe and in chapter 8, he will run away along the beach "until he dived into the forest..." His leaving the beach in favor of the forest signifies the end of any attempts at unity. 

By the end of the novel, Ralph has been hiding away in the undergrowth, in fear of his life and he stumbles onto the beach in his desperate attempts to survive. This is where he encounters the naval officer and it signifies the end of Ralph's terror. A motor boat is on the beach and as the other boys appear, the naval officer perceives a group of boys having "fun and games." The beach has exposed the boys as simply that although Ralph's responses indicate something far more sinister.