By: | August 26th, 2013. Denver International Airport is twice the size of Manhattan and is the second largest public works project in the world, second only to the Chunnel linking England and France. By land area, it is the largest US airport and third largest in the world. One hundred and ten million cubic yards ( yd.Â³) of earth were moved during the building of the project; this is equivalent to one third the amount of earth moved in building the Panama Canal.