Secret Boeing Test Facility

The Street View exactly matches an image that was published in the Seattle Times, but later removed:

http://seattletimes.com/ABPub/2013/08/14/2021614475.jpg

At a secret facility in Anacortes, more than 40 miles north of Boeing’s widebody-jet plant in Everett, a small group of engineers next month will begin testing advanced automation methods for building the soon-to-be-launched 777X jet.