After nine years of construction, the Hong Kong-Zhuhai-Macao Bridge (HZMB) officially opened to traffic on October 24. The HZMB is 55km long, making it the longest sea-crossing bridge in the world. It also includes the world's deepest underwater tunnel, which connects two artificial islands, at a length of 6.7km. Crowned as one of the “seven wonders of the modern world,” the HZMB was built using 400,000 metric tonnes of steel, and was designed to withstand magnitude 8.0 earthquakes and super typhoons.