sentences:  Pupil numbers at the school increased into four figures during the mid-1980s, necessitating the annexing of Crimea in the old Waterhall School in Fairwater to form the Ysgol Isaf (Lower School), which housed the First and Second forms (later Years 7 and 8) of the school from 1986.This split-site arrangement continued until the opening of Cardiff's second Welsh-medium Comprehensive School, Ysgol Gyfun Gymraeg Plasmawr, in 1998, from which point the Llandaff North site again housed the entirety of Glantaf's pupils.Education in Wales differs in certain respects from the systems used elsewhere in the United Kingdom.