Like the game series the Silent Hill movie features three layers of reality. Here are the different levels of Silent Hill explained.
SILENT HILL (2006) Explained
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Silent Hill: True Story & Real Town's History Explained
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SILENT HILL (2006) Explained
Any lore reason for the industrial looking ground in Silent Hill I? : r/ silenthill
Silent Hill Ending Explained: No One Leaves Silent Hill
Silent Hill (film), Silent Hill Wiki
SILENT HILL (2006) Ending Explained + Game Connections