China is set to unveil the world's longest cross-sea bridge, connecting Hong Kong, Macau and mainland China. 

The crossing, which took seven years to complete, is 55km-long and six lanes wide, comprising of four tunnels and four artificial islands.

Hong Kong, a former British colony, returned to China in 1997 under a "one country, two systems" agreement that ensured a separate legal system.


Source: Galileo Galilei Italian Institute

The multi-billion dollar project, which is being hailed as an international partnership, was reportedly built using more steel than 60 Eiffel Towers in the French capital, Paris.

The bridge will cut travel time in half, drawing mainland China, Macau and Hong Kong to within an hour's commute of each other.  

It has drawn criticism for over-spending and some fatal accidents.

However, Chinese authorities have hailed the finished project, inviting foreign media to inspect the crossing this week. 

"We hope that the friends from the press can take this opportunity to see the new accomplishment of China in the new era and fresh progress of the 'one country, two systems'", Song Ruan, deputy commissioner at the Chinese Ministry of Foreign Affairs, told reporters.


Image: Wikipedia

An estimated 40,000 vehicles a day are expected to use the new bridge, including shuttle buses running at 10-minute intervals. 

The mega bridge is one of two major infrastructure projects set to open in the region this year - the other is a high-speed rail link to mainland China.