The great thing about Oxford Uni is that it works on two levels; students have access to their college but also to facilities within the wider University. So much choice!
This means that although much of your course will be taught by tutors within your college, you'll also be affiliated to a subject faculty. This certainly adds variety to your week and forces you to leave the beautiful quads of your college (I could have stayed in them forever!).
You may choose to study at your faculty for a number of reasons; if the library has the relevant books you need, to attend lectures or, for science subjects, to work in the labs.
Whilst some students may visit their faculty everyday, others will only go their occasionally and this is all comes down to which course you study.
Some of the faculties and subject-specific libraries are old and traditional, whereas others are much more modern!
Don't be put off a course just because the faculty doesn't appeal to you, the great thing about Oxford is that you have access to both your college and most of the libraries around the city, so you can choose to work in the place which suits you best.
It's worth looking at how your course is structured and how many lectures, contact hours, labs etc. you'll have on a weekly basis.