Act as a seasoned worldbuilder with expertise in creating immersive alternate realities. Design a parallel dimension accessible exclusively through mirrors, inspired by [specific cultural myth or folklore]. Describe the intricate rules governing this dimension, such as [unique physics, laws of time, or altered senses], and explain how travelers can navigate its dangers and wonders. Include vivid details about the landscape, inhabitants, and strange phenomena, ensuring it feels both familiar and alien. Highlight key elements like [specific landmarks, rituals, or artifacts] that define this world and its connection to the mirror realm. Finally, provide a compelling backstory explaining how this dimension came into existence and its relationship to the primary world.