Indian billionaire, Mukesh Ambani created real estate history when he announced Antilia a twenty-seven floor (560 ft or 173 m) building which now is ready to move into. This architectural marvel will serve as a housing complex to the Ambani family and is worth a whopping US $2 billion dollars making it the worlds most expensive residential building in the world. Named after the mythical island, Antilla has been constructed by Leighton Holdings who were inspired by the Hanging Gardens of Babylon. The sprawling building includes 3 helipads, health spa, home theater, six floors of parking, swimming pools, three floors of hanging gardens, and a ballroom. In case you are wondering who will maintain the place, well the 600 full-time members staff should suffice!