Over the past year, we've learned plenty about what U.S. intelligence agencies do. But how much do we know about what these super-secretive bureaus actually look like? Photographer Trevor Paglen decided to find out.

His photos, published at the launch of of Glenn Greenwald's new media venture, were taken at night from a helicopter. Although he wasn't able to get permission from every agency he wanted to photograph, the shots he did get are impressive. Paglen has long had an interest in government secrecy and has photographed everything from top-secret satellites to black-project logos.

Since news about the NSA's scarily pervasive surveillance efforts broke last year, articles about the agency have mostly seemed to stick to one photo illustration: an undated image of NSA headquarters provided by the agency itself. There were no readily available recent photos of either the NSA or many of the numerous other agencies that make up the country's vast intelligence infrastructure. That's not right, says Paglen:

My intention is to expand the visual vocabulary we use to "see" the U.S. intelligence community. Although the organizing logic of our nation's surveillance apparatus is invisibility and secrecy, its operations occupy the physical world. Digital surveillance programs require concrete data centers; intelligence agencies are based in real buildings; surveillance systems ultimately consist of technologies, people, and the vast network of material resources that supports them.

The photos, commissioned by Creative Time Reports, are free for public use.

[NATIONAL RECONNAISSANCE OFFICE: The NRO is in charge of developing, deploying and operating secret reconnaissance satellites. With a budget request of $10.3 billion, it is the third-largest U.S. intelligence agency. It is headquartered in Chantilly, Virginia.]

[NATIONAL GEOSPATIAL-INTELLIGENCE AGENCY: The NGA is responsible for collecting, analyzing and distributing intelligence derived from maps and imagery. According to documents provided by Edward Snowden, the NGA's budget request was $4.9 billion last year – more than double its funding a decade ago. It is headquartered in Springfield, Virginia.]

[This undated image of NSA headquarters was provided by the agency. Image via Getty.]

[Lead image depicts NSA headquarters in Fort Meade.]