Officially opening in 1955, Chicago’s O’Hare airport is now the sixth largest airport in the world in terms of passengers per year. The airport is credited with supporting 450,000 jobs in the Chicago region and generating $38 billion of economic activity. With a strong commitment to sustainability, O’Hare houses the first airport-based rooftop aeroponic garden that provides airport vendors easy access to fresh produce, affords preferential treatment to compressed natural gas taxicabs, and runs a range of programs to encourage sustainable practices including wetlands restoration and soil reuse. It also is the site of the largest airport-based apiary in the world, which provides job experience for disadvantaged populations through its partnership with Sweet Beginnings.