Beijing's new Daxing Airport will be the biggest in the world when it opens later this year. Take a look inside the impressive $12 billion construction project.

• The construction of Daxing Airport in Beijing has, so far, cost just shy of $12 billion.
• China's aviation regulator stated that it would be allowing foreign carriers to choose which of Beijing's airports it would use.
• Beijing Daxing International Airport, due to open in September, is predicted to be the world's largest airport on its completion.

Less than 50 kilometres south of the capital of China, there's a massive construction project underway that, once finished, will officially become the world's biggest airport.

With the opening currently planned for September 30, 2019, the construction of Daxing Airport in Beijing has cost just shy of $12 billion so far.

On completion, the new airport will simply act as a second international airport for Beijing, to relieve existing pressure on Beijing's Capital International Airport.

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According to Reuters, carriers such as China Southern, China Eastern, and Beijing Capital Airlines will be relocated to the new Daxing airport, while airlines including Air China, Hainan Airlines and Grand China Air will remain at Beijing Capital International Airport.

Here's what the huge construction project looks like at the moment.

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Construction of Daxing airport began at the end of 2014

42 miles south of Beijing, the airport's construction started under President Xi Jinping in 2014.

So far the airport has cost at least $11.2 billion

One of the main purposes of the airport is to relieve pressure on Beijing's existing airport.

Initially, four runways will to be commissioned

Eventually, Beijing's Daxing International Airport will have seven runways in total.