18 giant infrastructure projects that could reshape the world

The world is full of unfathomably huge projects happening right under our noses.

Take the Hong Kong-Zhuhai-Macau Bridge, which will link three major Chinese cities in the country's quest to bring 42 million people together. Or Norway's plan to build the world's first fully-submerged floating tunnel to cut travel times between fjords in half.

Those efforts and many others illustrate how investing billions of dollars in enormous projects can collectively make the world a better place to live.

Here are some of the biggest projects the world has seen so far.