10 Things you didn’t know about Dubai’s Burj Khalifa (With Pictures)

2. A Lot of Cleaning

With an exterior that has about 26,000 individually cut glass panels, it makes one wonder just how that much glass gets cleaned regularly. Once again, the answer lies in something quite impressive. The Burj Khalifa has over 12 machines that weigh about 13 tons each that move along tracks on the outside of the building. A total of 36 cleaners get on and off of these machines to clean the reflective windows that are located on the outside.