What will the cities of tomorrow look like? Decades ago, people imagined the future looking like an episode of "The Jetsons," with flying cars and buildings perched high atop stilts.
While we aren't living in space cities just yet, modern architecture has brought us a taste of the future. Futuristic buildings and space-age skyscrapers dot city skylines all over the world, like in Shanghai's ultramodern Bund district and Dubai's man-made Palm Islands.
CNN iReporters sent in their favorites from their travels, including an amazing building designed to resemble a human eyeball, an American airport icon and a bizarre circular structure that defies the imagination.
What's the most futuristic building you've seen? Send your best photos to CNN iReport!