The document lists and describes 9 unique building structures currently under construction around the world. These include Aqua in Chicago, known for its rippling balcony design; the Chicago Spire, which will be the tallest building in the Western Hemisphere; and CCTV Headquarters in Beijing, featuring an unsupported corner design. The structures push the limits of design and engineering and include skyscrapers, hotels, and corporate headquarters with unconventional and striking appearances that will transform various skylines. The tallest, Burj Dubai in Dubai, is expected to reach 818 meters tall.