Construction of the Beijing Daxing International Airport finished on Sunday, five years after the project began in 2014, marking the start of the preparatory stage of the airport's operation.

It's being called the new gateway to China. It only takes around eight minutes to travel from its center to its farthest boarding gates.  

"Our designers learned from experiences in the world's airports and saw the inconveniences some can bring to passengers, such as getting to boarding gates. So, they've made an effort to shorten the travel time," said Nancy Yin, marketing director for China of ADP Ingenierie.

Building such a huge structure is a challenge. Five long concourses are connected with the largest single-body terminal in the world.

The steel structures are welded on the ground, then lifted up, "The margin of error is about a centimeter. It's a hard work, and sometimes even dangerous for our workers," said Guo Shuangchao, project manager of Beijing Construction Engineering Group.

Their hard work only makes the terminal more impressive, even in terms of scale alone. Inside, the unique use of windows and ceilings makes spaces appear cleaner and brighter.

"We use a high reflectance diffuse coating, which can reflect up to 98 percent of visible light. This makes the hall wider and brighter. The glass on the roof is also a special kind of glass, which has aluminum mesh inside it. This makes the sunlight shine through, but not glaring," said Lei Susu, who is the technology center director of Beijing Urban Construction Group.

Inside the terminal, six huge columns are under a cloud-shaped ceiling, which towers over the large business area, which was called "the Valley" by Lei and her coworkers. 

Underneath the terminal, over a thousand rubber isolation bearings are installed in pillars for earthquake resistance. They can reduce the required anti-seismic capacity of the terminal from eight to seven, and isolate the tremors from high-speed trains passing under the terminal.

To further improve travel experiences, five gardens are built at the end of each concourse, covering 10,000 square meters. They are named as China Garden, Silk Garden, Countryside Garden, Tea Garden, Porcelain Garden. Among them, the China Garden has hand-painted pavilions. 

The airport, located 46 km south of downtown Beijing, is designed to alleviate the pressure on Beijing Capital International Airport in the city's northeastern suburbs. It is expected to handle 45 million passengers annually by 2021 and 72 million by 2025.