The title of world's tallest building looks set to be snatched from Dubai's Burj Khalifa by Saudi Arabia's Jeddah Tower, now that funding for the last phase of its $US1.2 billion ($A1.66 billion) development has been secured.
Once the final, cloud-piercing reaches of the needle are built in 2020, achieving the planned height of 3,280 ft (1000 metres), the tower can claim the record.
The Kingdom Tower, as it is also known, will accommodate the world's highest observatory and be a mixed-use building with a gross floor area of 245,000 square metres. This will include offices, a 200-room Four Seasons Hotel, 121 serviced apartments and 360 residential apartments.
Work has already begun up to the 26th floor of the tower, located in Obhur, just north of Jeddah, on the Red Sea coast, but the finished building will have 200 floors.
"With this deal, we will reach new, as yet unheard of highs in real estate development," said Mounib Hammoud, chief executive officer of Jeddah Economic Company, the owner and developer of the Jeddah Economic City project, "and will fulfil the company's objective of creating a world-class urban centre that offers an advanced lifestyle, so that Jeddah may have a new iconic landmark that attracts people from all walks of society with comprehensive services and a multitude of uses."
"The overall layout of Jeddah Economic City is designed to accommodate a comprehensive, multipurpose environment, replete with aspects of a modern lifestyle over its 5.3 square kilometres, supported by world-class, state-of-the-art infrastructures."
The tower's design, by Adrian Smith + Gordon Gill Architecture, was inspired by the "folded fronds of young desert plant growth," the company's website states. "The way the fronds sprout upward from the ground as a single form, then start separating from each other at the top, is an analogy of new growth fused with technology."
Each of the tower's three sides features a series of notches that create pockets of shadow that shield areas of the building from the sun while providing outdoor terraces with views of Jeddah and the Red Sea.
The foundations will be 60m deep to cope with saltwater from the ocean.
The current holder of the title world's tallest building, the 2,722ft-high Burj Khalifa in Dubai, has a viewing platform at 1,821ft that opened to the public last year.
Another observation tower to open recently was the One World platform in New York, offering a completely new view of the city's famous skyline.
Before the Burj Khalifa, the open-air deck on China's Canton Tower, which opened in Guangzhou in 2011, held the record for world's highest at 1,601 ft. The ascent includes the world's longest spiral staircase and a horizontal "bubble tram", which rotates around the building.
With a top floor at 1.555 ft, the Shanghai World Financial Centre allows visitors to stand on a glass platform and look down on the viewing deck and city below.
The Tokyo Skytree, the world's second-tallest structure after the Burj Khalifa, has the fourth-highest deck at 1,480 ft. It can hold up to 2,000 people at a time.
Before these four new buildings, Toronto's CN Tower, built in 1976, held the long-standing record for highest platform. As for London, the Shard's 72nd-floor lookout is a measly 32nd on the list.
The Telegraph, London