While on the bus, with wi-fi of course, I googled "what to do in oxford." I found a 2 hour walking tour free of charge that got great reviews, so we decided to catch the tour at 2. You'll find these tours a lot in Europe, and they're great because it's usually students who give the tours, and you tip at the end based on how much you enjoyed it. This was the Footprints Tour, and I highly recommend it, it was great!
I didn't know but the University of Oxford is actually not one school, it's made up of 38 different universities. In addition to learning about the schools and such, we saw the building that the Harry Potter dining hall is in, and the hospital scenes are in. :) Apparently the wooden door, with the weird little elfish creature, inspired C.S. Lewis in The Chronicle of Narnia and the series The Lord of the Rings. Also Lewis Carroll wrote Alice in Wonderland in Oxford!