It is well known in the muggles’ world that Cambridge is the equivalence of Hogwarts(the other university expresses concern to the statement), and Trinity the best of its colleges(some 30 other colleges disagree). If you pay the toll, go to the big beautiful fountain at the centre of the Great Court, and knock 9 and 3/4 times(can’t be more, can’t be less), a raven will stroll towards you, and says in a screechy voice,
“Welcome back to the tavern, my dear friend.”