New York City’s subway system is one of the biggest in the world. And building it out is a logistical nightmare very few of its 4.3 million daily riders ever get to witness. Breaking Ground, a new photography exhibit by Patrick Cashin, offers a glimpse at the rugged, unfinished underworld of the MTA’s major capital projects.

The photos give an up-close look at what it takes to burrow through miles of bedrock. Most of the photographs look like the set of some dystopian sci-fi film, with massive rubble-filled caves and dingy lighting reflected off construction workers’ orange vests.

Cashin, formerly a Newsweek photographer, has been documenting the MTA’s subterranean excavations for 15 years. Pictured is a tunnel boring machine drilling into bedrock for the East Side Access project, which will link the Long Island Rail Road to Grand Central Terminal, as well as the work on the 7 Line extension to Manhattan’s west side.

Perhaps the most staggering photo features the tunnel beneath Second Avenue awaiting finishing touches to become the 96 St Q station. City officials have been planning the Second Avenue subway since World War I, and partial construction was done in the ’30s and ’70s, but it was halted during the ’70s financial crisis. Construction finally resumed in 2007. Cashin’s photograph shows a tunnel nearly a century in the making. The total cost of the 8.5-mile line, the first phase of which is set to open in December 2016, is expected to exceed $17 billion.

From these photos, you can see why such a project takes so long and costs so much–manmade machines versus miles of bedrock is a David and Goliath-like struggle.

Breaking Ground will be on view at Manhattan’s Bowling Green 4-5 station for a year.