The Twin Towers of the World Trade Centre in New York, the world's tallest from 1971 to 1973, were destroyed by plane hijackers as part of a 2001 plot by al-Qaeda leader Osama bin Laden.
Now, Saudi billionaire Prince Alwaleed bin Talal has launched a project to build the world's tallest tower in the Red Sea city of Jeddah.
The bin Laden family disowned their jihadist relative long before the September 11 terror attacks rocked the world.
If the latest building goes ahead, it will top Dubai's world's highest building, Burj Khalifa.
The tower, which will be part of a $US20 billion ($A18.3 billion) project north of Jeddah, would top Dubai's 828-metre Burj Khalifa, which was opened last year.
It will include a hotel, apartments and offices occupying an area of 500,000 square metres.