Burj Khalifa is a skyscraper in Dubai, United Arab Emirates, and currently the tallest man-made structure in the world, at 829.8 m (2,722 ft). It was designed to be the centerpiece of a large-scale, mixed-use development known as Downtown Dubai. Construction took over five years, and the skyscraper was officially opened in January 2010.Photograph: Donald Y Tong
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