Castle Rock gives Jack and his choir a place to differ from the more civilized people. Cas'tle, n. 1. heavily fortified residence 2. a safe, secure place; refuge"¦ Rock n. anything like or suggesting a rock, as in strength or stability; esp., a firm support, basis, refuge, etc. That is exactly what Castle Rock was. The fortified residence, that provided a firm support and refuge for Jack and his choir. Castle Rock represents a villains' hideout, where they can get away from the more civilized society, and live without rules. It represent the place and gathering of evil, much like the Joker has his hideout, along with the rest of the villains, and real life criminals have their hideouts to get away from the police.
Castle Rock provided a place for Jack and his choir to get away from Ralph's rule and Piggy's attempts to make a sound society on the island. It combines the fortified residence of a castle, with the primitive being of a rock. It is the savage hideout of Jack along with the other evils. In conclusion, Castle Rock is just one of the symbols in Lord of the Flies that makes you think and makes the book so great compared to many others.