A steampunk ocean floor metropolis bustling with life, where Victorian divers clad in ornate brass suits interact with imaginative marine creatures with Art Nouveau-inspired flowing designs, the architecture combining Gothic cathedrals with futuristic bioluminescent technology, glowing coral reefs illuminating the scenes, while an enormous octopus with clockwork tentacles tends to gardens of mechanical seaweed, the entire tableau watched over by a colossal transparent dome mirroring the cosmos, giving a glimpse into a starry sky teeming with airships and celestial phenomena.