This is the Packard Campus for Audio-Visual Conservation located inside Mount Pony in Culpeper, Virginia. From 1969 to 1988, the campus was a high-security storage facility operated by the Federal Reserve Board. The facility was decommissioned in 1992 and was transformed into the National Audio-Visual Conservation Center. Today it stores 6.3 million pieces of the library's movie, television, and sound collection.
 

This is a datacenter in a former Soviet nuclear bunker. Here's what is written on their site: "We found it [former nuclear bunker], refubrished it, equipped it and now we are ready to work."
Not bad.