Guided tour of some of the main buildings on campus, with a super insider guide - an MIT researcher, who gave us all his enthusiasm and gave us interesting information and anecdotes in burst:) It wasn't easy to keep up with him, also because of the size of the campus, but it was absolutely worth it.
Most of the buildings are open to the public, so you can visit them independently, but it is advisable to take the tour first to get an overall idea.