The idea of implementing the central skyscraper of the King Abdul Aziz Endowment Project in Mecca as the tallest clock tower in the world came about during the building of a group of seven hotel towers at the gate to the Great Mosque. The construction calculations for the towers had already been completed when, in late 2006, SL Rasch was asked to design the huge clock add-on. The specification: the tower top was to weigh no more than 82,000 tons.