Harvard Square is not a building, but the public space next to Harvard Yard and the Harvard Houses, the core of Harvard. There are lots of shops and restaurants.
How many students go here
Tours of Harvard would have to be probably two days long to begin to see the entire campus and even the majority of classrooms and research spaces. The tours generally highlight the more noteworthy buildings and history of the university. If you have a prospective student there may be tours where you can go into different schools of the university, but general tours aren't going to go into class settings.
The person can see whole yard
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