In China, construction is underway for one of the biggest airports in the world. Beijing Daxing Airport is about 42 miles south of the city center and will be accessible by high-speed train.

In an unexpected flip on the saying, "What's old is new again," the massive terminal at Beijing Daxing International Airport ...

The Daxing airport - said to be the world's largest terminal in a single building - is expected to receive a large amount of the 170m passengers the city expects to welcome by 2025.