Sport has always been very important in Cambridge. Many students try rowing because the Cam river is a good one to play this sport. There are many boat races between the different colleges. These are called "bumps": because the river is too small, boats start one behind the other. To win, a boat needs to hit (or "bump") the one ahead. Every year in London there is also the famous Boat Race between Oxford and Cambridge. Many other sports are played between colleges and universities.