Book excerpt: Have you ever wondered how the tallest buildings in the world are constructed? What makes them safe? Extreme Structures takes a fascinating look at how the coolest buildings and structures in the world were built, and what other kinds of structures are being planned for the future. Exciting color images and illustrations explain what the future of the designed world will look like. Exciting details include - the world's tallest towers - amazing high-tech housing, hotels, shopping malls, and museums - architectural secrets that helped build the Great Wall of China - the longest tunnels of the world - how theme park rides can teach us about design and structures - the world's most amazing bridges