Jeddah Tower or Jiddah Tower , previously known as Kingdom Tower and Mile-High Tower , is a skyscraper under construction in Jeddah, Saudi Arabia, at a preliminary cost of SR4.6 billion . It will be the centrepiece and first phase of a SR75 billion proposed development known as Jeddah Economic City that will be located along the Red Sea on the north side of Jeddah. If completed as planned, the Jeddah Tower will reach unprecedented heights, becoming the tallest building in the world, as well as the first structure to reach the one-kilometre-high mark (Initially planned to be high, the geology of the area proved unsuitable for a tower of that height). Jeddah Tower seeks to bring great changes in terms of development and tourism to the city of Jeddah, which is considered the most liberal city in Saudi Arabia.