Superb visual artist Trevor Paglen has taken unusual aerial photographs of the National Security Agency (NSA), the National Reconnaissance Office (NRO), and the National Geospatial-Intelligence Agency (NGA).  In Creative Time Reports, he explains:

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. If we look in the right places at the right times, we can begin to glimpse America’s vast intelligence infrastructure.

Paglen’s photographs generally sell for more than $10,000, but he has chosen to release these images into the public domain.  They are available here.