برج خليفة
The Burj Khalifa in Dubai, United Arab Emirates is the tallest structure in the world, standing at . Construction of the Burj Khalifa began in 2004, with the exterior completed 5 years later in 2009. The primary structure is reinforced concrete. Burj Khalifa was designed by Adrian Smith, then of Skidmore, Owings &amp; Merrill (SOM). He also was lead architect on the Jin Mao Tower, Pearl River Tower, and Trump International Hotel &amp; Tower.