I was at a small University in the South of England. It is a generally white campus, as in, the vast majority of students are white. At a glance, 85-90%. But interestingly, students who aren't white seem to cluster together in 'race' groupings, even if they are from various parts of the world. Students who are 'oriental' seem to group together. Students who are 'indian' group together. There was one mixed group, mixed Asian and black and white, who seemed like the "urban group", wearing "street" clothes and being loud.
This segregation, even if its self-imposed, doesn't seem to happen in London when I visit univeristies or colleges there. It may be coincidence that it appeared that way at that time on that day to me. Or it might be true of this univeristy - but I wonder why, if it is.