A little more than 40 years ago, Dubai was a tiny pearl-fishing village lined with dirt roads. Now it's the largest and most futuristic city in the world, the jewel of the United Arab Emirates (UAE). From manmade, palm tree-shaped archipelagos to jetpack-wearing firefighters and the world's tallest building, the city has a reputation for taking on insanely ambitious projects and executing them with swiftness and expertise. Now, the UAE has a vision to build an even crazier city—on Mars.