The MTA released some mesmerizing photos of the subterranean mega-project, started in 2007 and slated to be completed in 2016, when New York will run a brand new subway line through the tunnel from the Financial District all the way up to 125th Street along the East side.

The photos reveal some serious progress, and puts into jaw-dropping perspective the immensity of the task at hand.

And for some more photos, and specifically portraits of the construction workers doing all the dangerous mining, check out Gina Levay's "Sandhogs," or watch the documentary by the same name (see the trailer below).

PHOTO GALLERY Second Avenue Subway Photos