Create a mystical, ancient portal that serves as a gateway to the world of lucid dreaming. Visualize intricate, glowing runes and mystical symbols etched into the stone archway. In the center, a shimmering, iridescent light beckons the dreamer to enter, with a subtle, pulsing effect that suggests the infinite possibilities within. Incorporate misty, ethereal fog and subtle, starry lights to evoke a sense of wonder and enchantment.