The School of Pythagoras is the oldest building in St John's College, Cambridge, and the oldest secular building in Cambridge, England. To the north is Northampton Street. The School of Pythagoras was originally built around 1200, before even the University of Cambridge existed. It also predates St John's College, which was founded in 1511. It was initially a private house, but over the centuries it has had many uses. For a period it was a ruin. The reason for the name is unclear. The School of Pythagoras is now used as the College Archive Centre.