1: Dubai's Burj Khalifa is the tallest building in the world, but perhaps not for long. Saudi Arabia has announced plans to build a 1 kilometer (3,280 foot) tower into the sky, to be named the Jeddah Tower, scheduled for completion in 2020. The Burj Khallifa currently stands at 2,716 ft. (Photo by Matthias Seifert/Reuters)

A person dressed as the mascot of Tokyo Tower wears a face shield while waiting to greet patrons at the entrance of the 332.9m (1,092ft.) high tower on May 28, 2020, as the city's landmark reopened following the lifting on May 25 of the state of emergency, imposed due to the COVID-19 novel coronavirus outbreak. (Photo by Philip Fong/AFP Photo)

Base jumpers leap from the 300-metre high skydeck of Malaysia's landmark Kuala Lumpur Tower against the backdrop of the city's skyline in Kuala Lumpur on September 30, 2018 during the annual International KL Tower Base-Jump event. (Photo by Manan Vatsyayana/AFP Photo)

Six new Canadians take their oath of citizenship while harnessed on the CN Tower's “Edgewalk” 356 metres (1,168 feet) above Toronto, Ontario, Canada in a still image from video October 9, 2018. (Photo by CN Tower/Handout via Reuters)

People enjoy skating at the open air Christmas ice rink on the first floor of the Eiffel Tower after its reopening on December 19, 2016 in Paris The ice rink of about 200 square metres and on the first floor of the tower (57 metres above the ground) is open to the public until February 19, 2017. (Photo by Joel Saget/AFP Photo)

The television tower is pictured in Berlin, Germany, May 29, 2016. (Photo by Hannibal Hanschke/Reuters)

Two Bulgarian tourists pose in front of the Eiffel Tower in Paris on their last day in the capital on March 24, 2014. (Photo by Franck Fife/AFP Photo)