A mystical cave with a glowing, swirling portal at its center.

Beneath the vast expanse of a star-studded night sky, a mysterious and ethereal portal beckons from the depths of a cavern. The entrance to this portal is framed by rugged, jagged rock formations, their surfaces etched with the marks of time and the elements. The cavern itself is dimly lit, the darkness punctuated by the soft glow of distant stars and the ethereal light emanating from the portal. At the heart of the cavern, a swirling vortex of light draws the eye. This portal, a portal to another dimension, is a swirling mass of light and energy, its center a brilliant white that fades into a deep blue as it spirals outward. The light within the portal seems to pulse and shimmer, creating a mesmerizing effect that draws the viewer in. Rays of light from the portal pierce through the rocky walls, casting a mystical glow that illuminates the cavern and highlights the intricate textures of the surrounding rock. The atmosphere within the cavern is one of wonder and mystery. The cool blue tones of the scene evoke a sense of tranquility and otherworldliness, while the swirling light and starry sky add a touch of magic and intrigue. This image is a perfect representation of the unknown and the fantastical, inviting viewers to imagine what lies beyond the portal and to explore the mysteries that it holds.