A sprawling futuristic metropolis where every building, bridge, and skyscraper is grown rather than built—entirely composed of towering prickly pear cacti. The skyline glows with bio-luminescent cactus flowers, their petals pulsating with energy. Floating cactus pods serve as public transport, gliding through the city on vines that extend and retract like living monorails. The streets are paved with soft moss-like cacti, absorbing footsteps and leaving glowing imprints that fade after a few seconds. Giant translucent butterflies, engineered from hybrid succulent leaves, drift between the skyscrapers, pollinating the bio-mechanical ecosystem. In the heart of the city, a massive, ancient cactus beats like a heart, its golden sap flowing through transparent root-pipelines, fueling the entire civilization. The sky above is a deep twilight purple, dotted with floating pollen orbs that act as soft, organic streetlights.