You’ve got to check out these epic shots from far beneath New York City, where the long-heralded Second Avenue Subway line construction is underway.
This tunnel was dug by a tunnel boring machine - a piece of equipment that can weigh more than 450 tons and measure more than two and a half blocks in length! It's so big, it has to be brought in piece by piece and assembled below ground. Once it's working - it has the power of 12 jumbo jets.
Workers had to drill through solid rock underneath the streets of Manhattan. Much of the rock was more than three million years old!
Plans for the second avenue subway were initially pitched in the 1920s! Now, phase one of the project is set to be complete in 2016.