International design and innovation office CRA-Carlo Ratti Associati has unveiled design for a new office tower that will become the world's first "farmscraper", producing crops that can feed 40,000 people a year. Called Jian Mu Tower, the 218-metre high building will be built in Shenzhen, China and will incorporate a large-scale farm into its 51-story structure. The tower will house offices, a supermarket and a food court.