The saying sky's the limit is getting a whole new meaning owing to Saudi Arabia's Public Investment Fund planning to build a 2 km tall skyscraper in Riyadh. The megatall tower that would cost an eye-watering $5 billion to build would dwarf not only the tallest buildings in America and Britain but also the world's tallest building, the Burj Khalifa (2720 feet) in Dubai. With a height of 6561 feet (2000 meters), the proposed tower will stand tall as part of an 18-square-kilometer planned development to the north of Riyadh.

According to a report published by Middle East business intelligence (MEED) magazine, a design competition with a participation fee of $1m is underway for the record-breaking tower. Eight firms have been invited to participate in the design competition. The stalwarts include US-based firms Skidmore, Owings & Merrill (SOM), Adrian Smith & Gordon Gill Architecture, Kohn Pedersen Fox (KPF), and Gensler; 10Design, which is part of France's Egis; and Dubai-based Killa Design, responsible for the fantastic and award-winning Museum of the future.