East Side Access, a massive dig under NYC

Wikipedia:

East Side Access is an American public-works project being undertaken by the Metropolitan Transportation Authority (MTA) in New York City, New York, designed to bring the Long Island Rail Road (LIRR) into a new East Side station to be built below and incorporated into Grand Central Terminal in New York City’s Manhattan borough. It is expected to be operational by 2019.

Astonishing photos of this unbelievable undertaking.