It took 410 days to build the Empire State Building (381 meters tall); four years to erect the Golden Gate Bridge. The Pentagon took two years; the Alaska Highway just nine months. These days it takes longer to build an overpass.
Burj Khalifa known as Burj Dubai prior to its inauguration, is a skyscraper in Dubai, United Arab Emirates, and the tallest man-made structure ever built, at 828 m (2,717 ft). Construction began on 21 September 2004, with the exterior of the structure completed on 1 October 2009 (just over 5 years). The building officially opened on 4 January 2010, and is part of the new 490-acre flagship development called Downtown Dubai at the ‘First Interchange’ along Sheikh Zayed Road, near Dubai’s main business district.
1 World Trade Center (Freedom Tower) broke ground in 2006 and has a target completion of 2013 However, it took 5 years to start rebuilding.