Some 120 feet below the bustling streets of Manhattan are cavernous tunnels that will eventually connect the Long Island Rail Road to a new station linked to Grand Central Terminal.
The tunnels were carved out by two massive tunnel-boring machines, but work is currently being done underneath Grand Central.
The two machines made eight tunnel dives, completing the upper tunnel dives by November 2009, according to the Metropolitan Transportation Authority. In 2011, all the Manhattan tunnels were completed.
Here are some recent photos taken of the work beneath Grand Central:
