Desert Dunes in a Neon Underwater Cave

Inside an enormous underwater cave, a surreal desert chamber stretches along the seafloor. Fine golden desert sand forms rolling dunes that shimmer with bioluminescent algae. Neon cyberpunk signage and holographic advertisements are embedded in the cave walls and stalactites, casting electric pink, cyan, and violet glows on the sand. Rusted chrome drones drift through the water, cables snake between rock formations, and a shattered submarine hull lies half-buried. Above the dunes, schools of iridescent fish swirl in patterns like moving circuitry. A lone diver in a reflective neon-lit wetsuit navigates a glass tunnel, suspended above the sands. The atmosphere blends sci-fi grit with a desolate desert mood, all inside an underwater cavern with crisp detail, volumetric light shafts, and shimmering particles.