Imagine a futuristic underwater city where technologically advanced robots coexist with breathtaking underwater wonders, such as glowing sea creatures and ancient ruins. Create an image that showcases the harmony between man-made machines and the natural beauty of the ocean depths.

Visualise a city of the future, located beneath the surface of the ocean. This urban landscape is teeming with state-of-the-art robots, retaining an aesthetic coexistence with the sea's stunning natural splendors. Envision neon-tinged marine life, their bioluminescence illuminating the scene in a mesmerizing dance of light. Dotting the metropolis' skyline, observe historical architectural remnants as if silently narrating tales of bygone eras. Through this composition, highlight the harmony between human innovation, represented by these robotic technologies, and the inherent allure of the ocean's profound depths.