Act as a seasoned fantasy artist with expertise in creating immersive underground landscapes. Generate a highly detailed DALL-E image of a hidden cave illuminated by bioluminescent [blue and purple crystals], their glow reflecting off ancient [runestone carvings] etched into the walls. The cave should have a [misty, ethereal atmosphere] with subtle water droplets glistening on the crystal surfaces. Include intricate details like weathered symbols, faint glowing moss patches, and a narrow stone pathway leading deeper into the cavern. Use a cinematic composition with dramatic lighting to emphasize the mystery and grandeur of this forgotten sanctuary.