The Microsoft campus isn't a formal tourist attraction, but the surrounding area and the company's Visitor Center (when open) give some sense of the scale and culture of one of the world's most influential technology companies. The campus features manicured grounds, an internal transit system, and dozens of cafeterias that have been cited as models for corporate dining.
The building cluster around Building 17 houses the Microsoft Visitor Center, where exhibits trace the company's history from Bill Gates and Paul Allen's early work in Albuquerque to the present day. Displays include original products, advertising, and hardware milestones. Access has varied over the years — check current visiting policies before making a special trip. The surrounding streets and trails are open to the public and make for an interesting walk if you're curious about what a $3-trillion company's home base actually looks like.