Abu Dhabi will set out on the biggest project to date - a new micro-city with a round skyscraper taller than the Statue of Liberty and curved glass skin covering the area of four football fields. The spherical design and the proposed site pose numerous challenges, including design stability and a location that is half a mile out in the Persian Gulf and 25 feet under water. On top of everything, this skyscraper must be completed in just 30 montmonths' time.