A post-apocalyptic carnival set in a sunken city, where towering ruins rise from turquoise waters, draped in colorful coral and seaweed. Performers in steampunk attire, using salvaged mechanical parts, entertain crowds of aquatic creatures with a surreal mixture of circus arts and bio-luminescent light displays. The scene blends the decaying grandeur of Venetian architecture with whimsical elements of marine life and steam-powered contraptions, set against a sky painted with the vibrant hues of a setting sun. Bubbles drift lazily upward through the air, capturing refracted rainbows that glisten alongside the echoes of joyous laughter and crashing waves.