As with my recommendation of Barlborough Hall, this is the senior school to that, and absolutely you will need to obtain permission. It's history is that it has always been a school just its emphasis has changed from purely educating people for the priesthood to being a general secondary school.
The site is usually occupied by staff most days of the year and I have dropped the pin on the road entrance to the main car park.
Again, as an ex-pupil I found it easy to obtain permission but your mileage may vary. All you can do is phone up and ask or drop them an eMail as they are generally very responsive.
A suggestion: if of the right age, is to say you are considering sending your child here and want to gain as much perspective as possible :)
Land owner permission obtained.
View and discuss this location on Grey Arrows.
Co-ordinates: 53.30466, -1.316399 • what3words: ///kidney.employer.plodding