After about four years of construction, the major projects of Beijing Daxing International Airport are set to be completed today. The airport is expected to be one of the biggest and busiest in the world.

Today's milestone marks the start of the preparatory stage of the airport's operation, which is expected to start no later than September 30th. Daxing International is located 46 kilometers to the south of downtown Beijing, It was designed to take the pressure off the overcrowded Beijing Capital International Airport in the northeastern suburb. Daxing International will be able to serve 100 million travellers and handle eight hundred thousand take-offs and landings per year. The supporting facilities include high-speed rail and highways. Our reporter Ning Hong takes us on a tour through this engineering wonder.

NING HONG BEIJING DAXING INTERNATIONAL AIRPORT "This is the Beijing Daxing International Airport. It is a huge structure and we are now going inside."

NING HONG BEIJING DAXING INTERNATIONAL AIRPORT "This is really large. Look at the roof. you could see all the way over there. We are now on the departure level; these are the check-in desks. And over here, you could see all the way to the ground floor."

NING HONG BEIJING DAXING INTERNATIONAL AIRPORT "Now we've passed the security check and entering the main waiting hall. This is my favorite spot in this airport because it has the best view. We are now standing on a bridge, from here you could see the end of each corridors of this airport. It has six steel columns to hold the roof. It has a diameter of 180 meters. All together the waiting hall could hold the National Aquatics Center, also known as the Water Cube inside."

NING HONG BEIJING DAXING INTERNATIONAL AIRPORT "So this is really a must go place, a nice small garden to allow people to have some fresh air while waiting for their flights."

NING HONG BEIJING DAXING INTERNATIONAL AIRPORT "This is the China Customs. It has introduced the latest technology. Facial recognition, this is the camera here, everyone's face could be read here."