The original Microsoft building is in Albuquerque. Maybe this is the first one in Washington?
https://www.atlasobscura.com/places/historic-microsoft-plaqu...
https://www.atlasobscura.com/places/historic-microsoft-plaqu...
see https://devblogs.microsoft.com/oldnewthing/20080401-00/?p=22... and https://devblogs.microsoft.com/oldnewthing/20250401-00/?p=11...