India's richest person Mukesh Ambani is said to own the world's first billion-dollar house 'Antilia' in Mumbai's Altamount road. Considered the world's most expensive home, the 27-storey building is spread over 4 lakh square feet and rises 173 metres. Antilia features three helipads, a ballroom, a 50-seater cinema, nine elevators and a six-storey garage that can house 168 cars.