Wentworth Castle (not really a castle!) has had many incarnations. When I was a student in Sheffield in the early/mid 1960's it was a residential women's teacher training college. I have fond memories of happy times spent with some of the residents. It is now a college of education for adults without formal education qualifications. The extensive gardens and parkland around it are cared for by the National Trust.
en.wikipedia.org/wiki/Wentworth_Castle
en.wikipedia.org/wiki/Northern_College_(England)