Underwater City.

A sprawling underwater city concept art glowing beneath a deep ocean twilight zone. Domed habitats of reinforced glass and coral-inspired architecture cluster around a central spire pulsing with amber light. Transparent transit tubes connect districts while bioluminescent jellyfish drift between towers like living lanterns. Kelp gardens line terraced balconies and tiny submarines glide along designated lanes. The water shifts from deep indigo above to soft turquoise near the city lights.