The River Cam enters Cambridge from the south west of the city and heads north past many of the historic colleges of the University of Cambridge along the open area known as The Backs. After passing St John's College, it turns sharply and runs east, passing the weir at Jesus Green and the boathouses alongside Midsummer Common. Passing Chesterton, it turns north again and leaves the city, running a further before merging with the Great Ouse at Pope's Corner to the south of Ely.