Eco-friendly futuristic cityscape, recycled metal buildings, low-carbon concrete structures, solar-powered skyscrapers, green roofs, living walls, urban gardens, renewable energy systems, wind turbines, hydroelectric power plants, biodegradable materials, bamboo facades, reclaimed wood accents, natural fiber textiles, minimalist design, optimized building orientation, double glazing, thermal insulation, rainwater harvesting systems, grey water reuse, composting facilities, circular economy principles, zero-waste policies, futuristic transportation hubs.