SRI International In Menlo Park California (Underground Facility)

SRI Internation is a private research facility / Think Tank located in Menlo Park, California. They have an impressive list of patents and discoveries including being one of the first nodes in the precursor to the Internet the ARPANET along with UCLA, UCSB and University of Utah, inventor of the mouse, the LCD, optical read / write storage, LIDAR, Over the horizon radar, HDTV, various stealth technology etc.

I worked there one summer in the Credit Union and spent some time wandering about the buildings. there were alot of areas that I could not go into and the Credit union was in the basement, but several elevators seemed to indicate that there were at least 3 levels below that. But you had to key in a code to activate them. I was curious so I went to the county hall of records, and the plans on file indicate that there is only the basement area in the facility, but nothing more.

I was wondering if others have either worked here or heard about it? Its located just a few block from Stanford University.