The best thing about Cambridge - besides the beautiful architecture, friendly people, great mom & pop cafes - is the river Cam.
Sit by the river Cam and interact with the cute punters and amuse the tourists taking their conventional tours. Or, if you’re feeling particularly athletic, rent a punt out yourself and go punting down the river with a couple of your friends. But it’s really just sitting in the sun, surrounded by the gothic buildings—that’s what makes the experience.

Some great riverside spots—the Trinity Hall ledge by the balcony, and Magdalene College has a great view.