Classrooms provide clues to how you'll be taught. When taking the tour, ask to go into buildings, not just stand outside. We all have libraries and microscopes. Instead, you want to see what makes the college tick academically. Even an empty classroom provides clues to the way students are taught.
Posters tell a story about campus life.
Even the walls reveal clues. College newspapers provide invaluable information about the issues important to students there. Do a lot of people-watching. Alleto advises to go where other students gather and be a silent observer. Catch the flavor of student interaction in order to hear something other than the rehearsed talk from the tour guide.